Royal Chocolate Cake / Trianon

Here is a recipe for Royal cake - French dark chocolate mousse cake, also called Trianon - that consists of nut dacquoise, crispy layer of crepes Gavottes, and chocolate mousse. Just make it and enjoy the best chocolate goodness ever.

If you are a lover of decadent mousse chocolate cakes, this Royal cake (aka French cake Trianon) is for you.

In French, the Royal cake is gâteau Royal, where gâteau means cake, and Royal means Royal.

Another name for Royal cake is Royal au Chocolat, which means chocolate Royal.

The dessert is also called Versaillais or Trianon. According to one of the versions, the cake was named after a village Trianon near Versailles.

The cake itself is a three-layer dark chocolate mousse cake.

The bottom layer is dacquoise - a meringue with added almond and hazelnut flour. It tastes like French macarons, but its texture is softer and moist.

The middle layer is crunchy praline feuillantine made with crispy French crepes Gavottes, milk chocolate, chocolate paste, and hazelnut praline. This layer is the most delicious one and a signature of Royal chocolate cake.

The cake is topped with a creamy dark chocolate mousse based on whipping cream.

Three simple ingredients (chocolate, whipping cream, and milk) result in a dangerously addictive and delicious chocolate mousse.

Finally, the cake is covered with a cocoa mirror glaze.

Why you should try this recipe

This recipe for the Royal chocolate cake is easy enough to make, but it does call on some patience and special skills.

The chocolate taste and flavor of the cake are the best in this dessert: it is worth devoting your time to the pleasure of the mouth.

The freezing option is one of the best features for anyone who is looking to start their own home-based business.

The delicious taste will be preserved even after being prepared in advance, so you can enjoy it at any time.

The top of this cake is perfect for whatever you would like to do. It is really up to your creativity.

Ingredients

Here is a quick overview of what ingredients you will need. Follow the full recipe below for exact amounts and instructions. I recommend making this recipe as written for the best results. 

Crepes Gravottes (crêpe dentelle in French): these crispy and buttery cookies are a specialty of France. They are the star of the Royal cake.

You can purchase crepes Gravottes (you will need half of the box) or feuilletine flakes (crepes Dentelles crumbs) on Amazon. 

You can try to replace this ingredient with corn flakes; they are not the same, but they will work with the absence of authentic crepes-cookies.

Milk chocolate: use any brand of milk chocolate, for example, Lindt.

Chocolate paste: use Nutella hazelnut spread. 

Hazelnut praline paste: make it yourself or use a store-bought hazelnut praline.

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 or 60ml of cold water.

Almond flour, hazelnut flour/meal.

How to make Royal cake

To make the dacquoise, preheat the oven to 335 degrees F/170 degrees C. Using a flour sifter, sift powdered (icing) sugar, almond, and hazelnut flour.

In a separate bowl, whisk egg whites and gradually add granulated sugar until slightly firm (photo 1).

Once the meringue is ready, add icing sugar/flour mixture and gently mix with a spatula (photo 2).

Transfer the preparation in 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 lined with parchment paper (photo 3) or simply use a spoon.

Bake for 20 to 25 minutes. Let it cool in a frame (photo 4). 

To make the crunchy praline feuillantine,  crush crepes Gravottes roughly with hands or a rolling pin.

Melt milk chocolate in a bain-marie/water bath. In a bowl, place hazelnut praline, Nutella, and crepes chips and mix (photo 5). Add melted chocolate and mix again (photo 6).

Use a knife to loosen the dacquoise from the mold, but keep it inside. 

Pour the crunchy mixture over dacquoise, spread it on a thin layer with the back of a spoon (photo 7).

Then remove the mold and freeze the dacquoise for about 10 to 15 minutes (photo 8). 

To make the chocolate mousse, whip the cold whipping cream in a bowl to get the whipped cream and refrigerate (photo 9). 

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 (photo 10). Next, transfer the mousse to a pastry bag with a plain tip.

To assemble the cake, seal one side of the 8 inches/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, trying to raise it on the sides of the ring using a rubber spatula (photo 11).

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 (photo 12). Cover with a plastic film and freeze for at least 5 hours, better overnight.

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 boing actively, pout it over the sifted cocoa powder and gently mix, trying not to incorporate air.

Add the drained gelatin and mix it with an immersion hand blender. Then pour hot whipping cream and mix again.

Pass the mixture through a fine-mesh sieve and mix with a hand blender (photo 13). Let the glaze cool down to 86 degrees F/30 degrees C.

To glaze the cake, take the dessert out of 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 acetate collar.

Pour the glaze over the cake and remove the excess glaze with a bent spatula, passing it over the top once (photo 14).

Transfer the dessert to a cake board using two metal spatulas. Place the cake in the fridge to thaw for 3 to 4 hours.

Recipe variations

The layers remain constant in the traditional French Royal chocolate cake while the cake's decoration varies.

The most popular way to decorate the cake is with a chocolate glaze, but you can also coat it in cocoa nibs at the bottom.

One decoration that you can do for your special day, if desired, would be to cover the edges of the dessert with a chocolate band and sprinkle the top of the cake with cocoa powder.

To make the band, cut a strip of the acetate collar equal to the diameter and height of the edge of the cake.

Cover it with melted chocolate on one side, using a bent spatula, and let set at room temperature for 1 minute.

Place the chocolate film all around the cake, chocolate inside. Refrigerate for 10 minutes and gently remove the film.

Then dust the top of the cake with cocoa powder and prearrange the cake pieces with the back of the knife’s blade.

But the easiest way to make the Royal cake special is by covering the sides of the cake with chocolate shavings and dusting cocoa powder on top.

Storing and freezing

Store the assembled cake in the refrigerator for 2 to 3 days.

If you want to freeze the cake for longer, wrap it unglazed with plastic film to prevent the absorption of freezer odors.

Keep the cake frozen for up to two to three weeks. Then, glaze the cake on the day of serving and let it thaw for 3 to 4 hours in the refrigerator.

Expert tips

1. Do not over whisk egg whites while making the dacquoise. They have to be slightly firm to incorporate the nut flour.
2. Spread the chocolate mousse well inside the mold, using a rubber spatula to avoid trapping air in the cake.
3. Once the cocoa mirror glaze is applied, use a bent metal spatula to remove the excess with a single pass over the top of the cake to avoid making marks.
4. Take the dessert out of the fridge about 20 minutes before tasting (the cold temperature alters the taste of chocolate).

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Theinitiallyal 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. If the nutrition information is important to you, you should independently verify it using your preferred tool. Under no circumstances will Baking Like a Chef be responsible for any loss or damage resulting from your reliance on the nutritional information. You are solely responsible for all decisions about your health and ensuring that any nutritional information provided is accurate. Please, read the disclaimers in our Privacy Policy.

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.