Quick Summary: Royal chocolate cake, also called Trianon or gâteau Royal, is a French dark chocolate mousse cake with three layers: a nutty almond-hazelnut dacquoise base, a crunchy praline feuillantine middle, and a smooth dark chocolate mousse, finished with a cocoa mirror glaze. It can be made ahead and frozen.
What is a Trianon cake?
A Trianon cake is the French name for the Royal chocolate cake, also written gâteau Royal or Royal au Chocolat. The cake is also called Versaillais or Trianon gateau. According to one version, the cake was named after the village of Trianon near Versailles.
Unlike the general Royal cake description above, the "Trianon" name specifically points to this classic three-layer chocolate mousse entremet built on a nut dacquoise with a praline crunch.
Why you'll love this recipe
- Layered textures: Nutty dacquoise, crunchy praline feuillantine, and smooth chocolate mousse in every slice.
- Make-ahead friendly: The cake freezes well, so you can prepare it in advance and serve it whenever you need.
- Deep chocolate flavor: Three simple ingredients (chocolate, whipping cream, and milk) build a rich, dark chocolate taste.
- Customizable finish: Top it with a cocoa mirror glaze, chocolate shards, or whatever decoration you like.
Ingredients
For ingredients and detailed instructions, refer to the recipe card below.
- Crepes Gavottes (crêpe dentelle in French): these crispy and buttery cookies are a specialty of France. You can purchase crepes Gavottes (you will need half of a box), or feuilletine flakes (crepes Dentelles crumbs) on Amazon. You can try replacing this ingredient with cornflakes. They are not the same, but they will work in the absence of authentic crepe cookies.
- Milk chocolate: use any brand of milk chocolate, for example, Lindt.
- Chocolate paste: use Nutella hazelnut spread.
- Hazelnut praline paste: make hazelnut praline paste yourself or use store-bought.
- Egg whites: separate egg whites from egg yolks using an egg separator. Then bring the whites to room temperature.
- Sugar: the recipe calls for granulated sugar.
- Icing sugar: make it yourself with a coffee grinder or store-bought powdered sugar.
- Whipping cream: use a chilled bowl to whisk cold whipping cream.
- Milk: the recipe calls for whole milk.
- Dark chocolate: use high-quality dark chocolate, such as Valrhona dark chocolate.
- Cocoa powder: the most flavorful cocoa powder is produced by the European brand Valrhona, although you can use any other brand.
- Gelatin: use gelatin sheets with a strength of 200 bloom. To substitute sheet gelatin in the recipe, use 8 g of powdered gelatin and ¼ cup (60 ml) of cold water.
- Almond flour, hazelnut flour/meal.
Equipment
To make this Royal chocolate cake, you will need the following tools:
- Flour sifter: to sift the icing sugar and flour for the dacquoise.
- Pastry bag: to pipe the dacquoise batter and the mousse.
- Ateco plain pastry tip 809: a plain round tip for piping the dacquoise.
- Mousse cake mold: to shape and hold the layers.
- Parchment paper: to line the baking sheet.
- Rolling pin: to crush the crepes Gavottes for the feuillantine.
- Rubber spatula: to fold the meringue and mix the mousse.
- Bent spatula: to spread the mousse and smooth the glaze.
- Immersion blender: for a smooth mirror glaze.
- Blow torch: to warm the ring and unmold the cake cleanly.
How to make Royal cake
Step 1. To make the dacquoise, preheat the oven to 335°F (170°C). Using a flour sifter, sift powdered (icing) sugar, almond, and hazelnut flour.
Step 2. In a separate bowl, whisk egg whites, and gradually add granulated sugar until slightly firm (photo 1).
Step 3. Once the meringue is ready, add the icing sugar/flour mixture and gently mix with a spatula (photo 2).
Step 4. Transfer the preparation to a pastry bag with Ateco plain pastry tip 809. Adjust a mousse cake mold to 7 inches (18 cm) in diameter.
Step 5. Pipe a spiral inside the mold placed on a baking sheet lined with parchment paper (photo 3), or use a spoon to do so.
Step 6. Bake for 20 to 25 minutes. Let it cool in a frame (photo 4).
Step 7. To make the crunchy praline feuillantine, crush crepes Gavottes roughly with your hands or a rolling pin.
Step 8. Melt milk chocolate in a bain-marie (water bath). In a bowl, place hazelnut praline, Nutella, and crepe chips and mix (photo 5). Add melted chocolate and mix again (photo 6).
Step 9. Use a knife to loosen the dacquoise from the mold, but keep it in the mold.
Step 10. Pour the crunchy mixture over the dacquoise, and spread it into a thin layer with the back of a spoon (photo 7).
Step 11. Then remove the mold and freeze the dacquoise for about 10 to 15 minutes (photo 8).
Step 12. To make the chocolate mousse, whip the cold whipping cream in a bowl until stiff peaks form, then refrigerate (photo 9).
Step 13. Melt dark chocolate broken into small pieces in a bain-marie/water bath.
Step 14. Bring milk to a boil, pour it over the melted chocolate, and mix with a rubber spatula until smooth.
Step 15. When the chocolate mixture is lukewarm, add it to the whipped cream and mix with a spatula as fast as possible (photo 10). Next, transfer the mousse to a pastry bag with a plain tip.
Step 16. To assemble the cake, seal one side of the 8-inch/20 cm cake ring with a plastic film and place it on a wooden board or a baking sheet.
Step 17. Insert an acetate collar inside the ring. Poach the chocolate mousse in the mold, then raise the sides of the ring using a rubber spatula (photo 11).
Step 18. Take the dacquoise disk from the freezer, turn it over, and place it over the mousse (dacquoise side up).
Step 19. Slightly press the disk and remove the excess mousse with a bent spatula (photo 12). Cover with a plastic film and freeze for at least 5 hours; better overnight.
Step 20. To make the cocoa mirror glaze, soak gelatin sheets in cold water for 10 minutes.
Step 21. Heat whipping cream over low heat and set aside. Pour water and sugar into a saucepan and bring to a boil.
Step 22. Once the sugar syrup starts boiling actively, pour it over the sifted cocoa powder and gently mix, avoiding air bubbles.
Step 23. Add the drained gelatin and mix it with an immersion hand blender. Then pour hot whipping cream and mix again.
Step 24. Pass the mixture through a fine-mesh sieve and mix with a hand blender (photo 13). Let the glaze cool down to 86°F (30°C).
Step 25. To glaze the cake, remove the dessert from the freezer. Place the cake on a wire rack or a plate, which is itself placed on a baking sheet, to collect the excess glaze.
Step 26. Remove the plastic film, mold (heat the sides of the ring with a blow torch), and the acetate collar.
Step 27. Pour the glaze over the cake, then remove the excess with a bent spatula, passing it over the top once (photo 14).
Step 28. Transfer the dessert to a cake board using two metal spatulas. Place the cake in the fridge to thaw for 3 to 4 hours.
Expert tips
- Do not overwhisk the egg whites when making the dacquoise. They have to be slightly firm to incorporate the nut flour.
- Spread the chocolate mousse well inside the mold, using a rubber spatula to avoid trapping air in the cake.
- Once the cocoa mirror glaze is applied, use a bent metal spatula to remove excess in a single pass over the top of the cake, avoiding marks.
- Take the dessert out of the fridge for about 20 minutes before tasting it (cold temperatures alter the chocolate's flavor).
Recipe variations
The layers of the traditional French Royal chocolate cake stay the same, so most variations come from how you finish and decorate it:
- Chocolate glaze: The classic finish is a cocoa mirror glaze poured over the chilled cake.
- Cocoa dusting: Coat the top with cocoa powder and cover the sides with chocolate shavings for a simple look.
- Chocolate collar: Spread melted chocolate on an acetate strip, wrap it around the cake, chill for 10 minutes, then peel off the acetate for a smooth chocolate band.
- Decorative top: Dust with cocoa powder and mark the portions with the back of a knife, or add chocolate shards for a finishing touch.
Storing & freezing
Store the assembled cake in the refrigerator for 2 to 3 days.
If you want to freeze the cake for longer, wrap it in plastic wrap to prevent freezer odors from absorbing into it. Keep the cake frozen for up to two to three weeks. Then, glaze the cake on the day of serving and let it thaw in the refrigerator for 3 to 4 hours.
Troubleshooting tips
- Runny or flat dacquoise: The meringue was underwhipped or overmixed when the nuts were folded in. Whip the whites to stiff peaks, then gently fold in the dry ingredients.
- Sticky or soft dacquoise: It is underbaked, or the humidity got to it. Bake until dry to the touch and store it airtight until assembly.
- Runny chocolate mousse: The cream was not cold or was underwhipped, or the melted chocolate was too warm. Chill the cream, whip to soft peaks, and let the chocolate cool before combining.
- Dull or streaky mirror glaze: The glaze was poured at the wrong temperature. Use a thermometer and pour at about 90°F (32°C) over a well-chilled cake.
- Soggy praline layer: The feuillantine sat too long before assembly. Spread it just before adding the mousse so the crepes stay crisp.
Recipe FAQ
What is a Trianon cake?
A Trianon cake is the French name for the Royal chocolate cake (gâteau Royal). It is a three-layer chocolate mousse entremet made with a nut dacquoise, a praline feuillantine crunch, and dark chocolate mousse, named after the Grand Trianon at Versailles.
Why is it called a Royal cake or a chocolate Royale cake?
The names Royal cake, chocolate royal cake, and chocolate royale cake all refer to the same French dessert, gâteau Royal or Royal au Chocolat. "Royal" reflects its rich, refined chocolate character.
Can you make the Royal cake in advance?
Yes, you can make this dark chocolate mousse cake up to 1 day in advance and keep it frozen. Then glaze the cake on the day of serving.
Is Royal chocolate cake gluten-free?
No. While the dacquoise base uses nut flour, the praline feuillantine layer is made with crepes Gavottes, which contain wheat, so this cake is not gluten-free.
What is dacquoise in a Trianon cake?
Dacquoise is a baked nut meringue, here made with almond and hazelnut flour. It forms the sturdy bottom layer of the Royal chocolate cake.
What is feuillantine or praline crunch?
Feuillantine is a crispy layer made from crushed crepes Gavottes mixed with hazelnut praline and chocolate. It gives the Trianon cake its signature crunch.
How long does the Royal cake keep?
Stored in the refrigerator, the assembled cake keeps for two to three days. Frozen without the glaze, the layers keep for up to one month.
Love cakes? Try these next!
If you love this Royal chocolate cake, try these other chocolate-based cakes next:
- Chocolate Ganache Cake
- French Chocolate Cake (Suzy Cake)
- Chocolate Fondant (Fondant au Chocolat)
- Moelleux au Chocolat
- Raspberry Lava Cake
- Chocolate Sponge Cake
Browse all the Cake Recipes
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PrintRecipe card
Royal Chocolate Cake (Trianon / Gâteau Royal)
Royal chocolate cake (Trianon or gâteau Royal) is a French dark chocolate mousse cake made of nut dacquoise, a crispy layer of crepes Gavottes, and dark chocolate mousse. Follow this recipe to make Royal chocolate cake at home.
- Prep Time: 1 hour 30 minutes
- Cook Time: 30 minutes
- Total Time: 2 hours (plus chilling time)
- Yield: 8 1x
- Category: Cakes
- Method: Baking
- Cuisine: French
Ingredients
For the dacquoise:
- 3 ½ tablespoons (55 g) egg whites (see note #1)
- 2 ½ tablespoons (35 g) granulated sugar
- ½ cup + 1 teaspoon (65 g) icing sugar
- ⅓ cup (30 g) almond flour
- 2 tablespoons (15 g) hazelnut flour/meal
For the crunchy praline feuillantine:
- 1.7 oz (50 g) crepes Gravottes
- 1.7 oz (50 g) milk chocolate
- 1.7 oz (50 g) hazelnut spread Nutella
- 1.7 oz (50 g) Hazelnut Praline Paste
For the chocolate mousse:
- 2 cups + 3 tablespoons (500 ml) whipping cream
- 5 tablespoons (75 g) whole milk
- 7 oz (200 g) dark chocolate
For the cocoa mirror glaze:
- ⅔ cup + 4 ½ tablespoons (210 g) granulated sugar
- 5 tablespoons (75 g) water
- 9 ½ tablespoons (70 g) cocoa powder, unsweetened
- ½ cup + 2 tablespoons (145 ml) whipping cream
- 3 ⅓ gelatin sheets (8 g powdered gelatin - see note #2)
*Don't you have the correct baking pan on hand right now? Try this simple Cake Pan Converter!
** If needed, please refer to Baking Conversion Charts.
Instructions
- To make the dacquoise, preheat the oven to 335°F (170°C). Using a flour sifter, sift powdered (icing) sugar, almond, and hazelnut flour. In a separate bowl, whisk the egg whites, then gradually add granulated sugar until slightly firm. Once the meringue is ready, add the icing sugar/flour mixture and gently mix with a spatula.
- Transfer the preparation to a pastry bag with Ateco plain pastry tip 809. Adjust a mousse cake mold to 7 inches/18 cm in diameter. Pipe a spiral inside the mold placed on a baking sheet with parchment paper, or simply use a spoon. Bake for 20 to 25 minutes. Let it cool in a frame.
- To make the crunchy praline feuillantine, roughly crush the crepes Gavottes with your hands or a rolling pin. Melt milk chocolate in a bain-marie (water bath). Place hazelnut praline, Nutella, and crepe chips in a bowl and mix. Add melted chocolate and mix again.
- Use a knife to loosen the dacquoise from the mold, but keep it in the mold. Pour the crunchy mixture over the dacquoise, and spread it into a thin layer. Then remove the mold and freeze the dacquoise for about 10 to 15 minutes.
- To make the chocolate mousse, whip the cold whipping cream in a bowl until stiff peaks form, then refrigerate. Melt dark chocolate broken into small pieces in a bain-marie/water bath. Bring milk to a boil, pour it over the melted chocolate, and mix with a rubber spatula until smooth. When the chocolate mixture is lukewarm, add it to the whipped cream and mix with a spatula as fast as possible. Transfer the mousse to a pastry bag with a plain tip.
- To assemble the cake, seal one side of the 8-inch/20 cm cake ring with a plastic film and place it on a wooden board or a baking sheet. Insert an acetate collar inside the ring. Poach the chocolate mousse in the mold, raising it up the sides of the ring with a rubber spatula. Take the dacquoise disk from the freezer, turn it over, and place it over the mousse (dacquoise side up). Slightly press the disk and remove the excess mousse with a bent spatula. Cover with a plastic film and freeze for at least 5 hours.
- To make the cocoa mirror glaze, soak gelatin sheets in cold water for 10 minutes. Heat whipping cream over low heat and set aside. Pour water and sugar into a saucepan and bring to a boil. Once the sugar syrup starts boiling actively, pour it over the sifted cocoa powder and gently mix, avoiding air bubbles. Add the drained gelatin and mix it with a hand blender. Then pout hot whipping cream and mix again. Pass the mixture through a fine-mesh sieve and mix with a hand blender. Let the glaze cool down to 86°F/30°C.
- To glaze the cake, remove the dessert from the freezer. Place the cake on a wire rack or a plate, which is itself placed on a baking sheet to collect the excess glaze. Remove the plastic film, mold (heat the sides of the ring with a blow torch), and the acetate collar. Pour the glaze over the cake, then remove the excess with a bent spatula, passing it over the top once. Transfer the dessert to a cake board using two metal spatulas. Place the cake in the fridge to thaw for 3 to 4 hours.
Notes
- 55 g egg whites approximately equal 1 ½ raw egg whites from extra-large chicken eggs.
- To substitute sheet gelatin, use 8 g of powdered gelatin and ¼ cup (60ml) of cold water.
- Do not overwhisk the egg whites when making the dacquoise. They have to be slightly firm to incorporate the nut flour.
- Spread the chocolate mousse well inside the mold, using a rubber spatula to avoid trapping air in the cake.
- Once the cocoa mirror glaze is applied, use a bent metal spatula to remove excess in a single pass over the top of the cake, avoiding marks.
- Store the decorated cake in the fridge for 2 to 3 days.
- Take the dessert out of the fridge for about 20 minutes before tasting it (cold temperatures alter the chocolate's flavor).
Nutrition
- Serving Size: 1 slice
- Calories: 635
- Sugar: 58.8 g
- Sodium: 60 mg
- Fat: 41.1 g
- Saturated Fat: 23.6 g
- Carbohydrates: 70.2 g
- Fiber: 5 g
- Protein: 8.7 g
- Cholesterol: 97 mg
The nutritional information has been calculated using an online recipe nutrition calculator such as Verywellfit.com and is intended for informational purposes only. These figures should be used as a general guideline and not be construed as a guarantee.
The recipe was adapted from http://www.elle.fr. It was originally published on May 11, 2018. The recipe has been revised to include improved content and photos. All posted pictures are mine.
Veena Azmanov says
This cake is heavenly. Mouth melting and delicious. I just can't wait to have a bite.
Irina says
Thank you very much, Veena! I hope you will make this cake one day. 🙂
Rika Livingston says
That's a truly royal cake! Thanks for sharing very useful steps!
Irina says
You are very welcome, Rika!
Emily Liao says
Wow, this cake was absolutely amazing! So rich in flavor with the different layers.
Irina says
You made it! Thanks for letting me know, Emily!
Lisa Huff says
Oh, this has my name written all over it! So much chocolate goodness. I love that mirror glaze too!
Irina says
Lisa, thanks for stopping by. Please, enjoy the recipe!
Tara says
Such a gorgeous, decadent cake! So sophisticated. I love that chocolate mirror glaze and the layers.
Irina says
Thank you very much, Tara!
Mary says
A project, but totally worth it! Love all the flavors and textures - so refined!
Irina says
The cake seems to be complicated, but it is not. Please, enjoy the recipe, Mary. And thanks for stopping by. 🙂
Courtney says
This is one gorgeous and decadent cake! Perfect for chocolate lovers.
Irina says
Yes, it is tasty. Everyone tried the cake at our home loved it! Thanks for your comment, Courtney.
Emily Liao says
Wow, this cake was so rich and decadent! I loved the flavors in this, and it came out perfectly.
Irina says
It is great to hear, Emily. Thanks for your feedback!
Marlynn says
Oh my goodness, this cake is amazing!! It's a chocolate lover's dream!
Irina says
Sure thing, Marlynn! 🙂 Please, enjoy the recipe.
Bintu says
Oh my, this cake looks so decadent and delicious - I'd love a slice right now!
Irina says
Yes, the cake is one of the best chocolate cakes I have ever made. Please, enjoy the recipe, Bintu!
Anita says
What an absolutely stunning cake! This will be perfect for a birthday cake. I wish we are neighbors so I can come and try all your lovely desserts, Irina. 🙂
Irina says
Thank you very much, Anita. Your idea sounds wonderful 🙂
Ashley says
What a royal recipe!! I am sending off to my baker friend, and telling her she *has* to make this!! Sounds so so good!
Irina says
Thank you very much, Ashley! I hope you will be able to taste it. 🙂
Emily says
This royal chocolate cake is so delicious and beautiful! I love that you can make it ahead of time and freeze it before decorating, that's so helpful to know!
Irina says
Emily, I love this freezing option too! Please, enjoy the recipe. And thank you for your comment.
Janelle says
Oh wow, this cake is decadent. It was a crowd winner 🙂
Irina says
Perfect! Thanks for letting me know, Janelle!
Alexandra says
Such an impressive cake - I love the decadence and the beautiful texture!
Irina says
Thank you very much, Alexandra!
Laurie says
What a gorgeous cake it is! I bet it tastes amazingly delicious. I need to make it ASAP!
Irina says
Thank you, Laurie! Happy baking and enjoy it! 🙂
Anvayee says
Thank you for such an amazing recipe!! I made it for the first time, and the cake was soooo delicious., Also, I followed your hazelnut praline recipe, and it turned out perfect. I’m definitely going to make it again. 😊
Irina says
Thank you very much, Anvayee! I am so glad to hear that you enjoyed both recipes.
Jeanette says
May I clarify about substituting sheet gelatin with powdered gelatin? When using sheet gelatin, after soaking in water --> drain. With powdered, do I just use the whole mixture after mixing 8 g with 60 ml water? And will I still need the hand-blender steps? Thanks in advance!
Irina says
Thanks for your interest in the recipe, Jeanette! Yes, please, use the whole gelatin mixture and follow the recipe, including the blender step. Happy baking and enjoy it! Please, let me know how it went. 🙂
Hannah Jordan says
Hello! This looks so delicious. I plan on making this for Christmas, but I have one question...I am a little nervous about chocolate mousse's stability since your recipe doesn't include egg yolks, and I live at a high altitude (Colorado Springs). Will the mousse set up firmly enough?
Irina says
Hi Hannah, thanks for your interest in the recipe. It is a difficult question for me to answer, to tell the truth. But the mousse thickens while you make it. I really hope and believe that it should be fine. The best is to try to test it using 1/4 of the amount of chocolate and re-calculate other ingredients. You could make it in the morning on December 23. Let's say that in the afternoon, you will get the test results. Please, let me know how it went. Happy holidays!!!
Suzanne says
Might I suggest that a better substitute for the French cookies is to use plain waffle cones? Not the ones that are pale and thin but the real waffle cones, and to purchase the ones that are not lined in chocolate. Basically, the same ingredients as Gravottes. And because the hazelnut brittle, milk chocolate, and hazelnut spread are sweet, the waffle cones don’t add more sweetness but just crunch. This is a nice mix
Irina says
Thank you very much, Suzanne, for your suggestion! It is beneficial for those who cannot get/purchase Gravottes. 🙂
Viviana Amortegui says
Hi, how are you? I am a bit confused about the cake assembling. Would you please send me a video?
Irina says
Hello Viviana, thank you for your ineterst in the recipe. I am sorry, but I do not have a video on making and assembling the cake. But let me help you here. First, you need to cover the bottom of the cake ring with plastic wrap, like making a plastic bottom. Them, please, place an acetate collar inside the ring (along the sides). Next, poach all the mousse in the mold, and using a rubber spatula, raise it on the sides up to the top of the ring. Finally, place the dacquoise disk on top and press it slightly. Why raise the mousse to the top of the ring? Because the dacquoise disk is smaller in diameter than the diameter of the assembled cake. So, the disk has to be surrounded by the mousse. Please, let me know if understood my explanation.
Nancy says
I haven’t made this yet. The following sentence does not make sense.: “Poach the chocolate mousse in the trying to raise on the sides of the ring.” Would you please explain?
Irina says
Hello Nancy, I am so sorry for the wrong wording in that sentence. I think it was a result of copy-pasting... I corrected the recipe, thank you. Please, read as "Poach the chocolate mousse in the mold, trying to raise it on the sides of the ring using a rubber spatula." You should cover the bottom of the mold with the mousse and rise it on the sides, so the inserted layers will be covered with the mousse around. Please, let me know if my explanation is clear and understandable. Thanks!!
Steve says
I am looking forward to trying this recipe, I've seen recipes for the Trianon Cake, but your recipe broke things down to easy-follow instructions. Some may think it is too complicated, but I am looking forward to making this. Do you have a recipe for the crepes Gravottes? I find it difficult to source or very expensive. Thank you.
Irina says
Hello Steve, You found the right recipe to make. 🙂 It is absolutely delicious! I once searched the French recipe for crepes Gravottes and found it, but I've never made it myself. I always purchase it on Amazon. You can also look for Feuilletine Flakes, aka Crepes Dentelles. Finally, you can replace this ingredient with crunchy cereals. On Christmas, I made the same recipe to make a Buche de Noel (press the link to open it). The readers are asking to post its recipe; I will do this in the membership area. To access it, you should subscribe to my emails. Happy baking and let me know how it went!
Grace says
Looks magnificent! If we are doubling the recipe to make a bigger cake, what measurement would you suggest for making the cake mold for the mousse and dacquoise, please?
Irina says
Hello Grace, Thanks for your interest in the recipe. You will love the cake; it is guaranteed. Trust me 🙂 As for doubling the recipe, I used this cake pan calculator on the website https://www.bakinglikeachef.com/cake-pan-converter/ and played around to figure out the answer. So, the recipe is created for 8 inch (20 cm) mold. If you double the recipe, you will need 11.5 inches (29 cm) mold.
Theresa Lemieux says
Wondering why boil rather than just heat the milk? My smooth melted chocolate looked kinda of curdled after the addition. Stirring slowly hoping it’ll come back together for the mousse.
Irina Totterman says
Hello Teresa, you should heat the milk until the first bubbles. Your chocolate should melt well. Please let me know how it went.