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 rich mousse chocolate cakes, this Royal cake (aka French cake Trianon) is for you!

It is a classic French dessert that is made with a crispy almond and hazelnut meringue - dacquoise - and crunchy praline feuillantine (French pronunciation: ​[paj.te fœj.tin]). Then it is topped with a thick layer of rich dark chocolate mousse. Finally, it is covered with a cocoa mirror glaze.

Royal cake in French

Royal cake is gâteau Royal in French, where gâteau means cake, and Royal means Royal. Another name of Royal cake in French is Royal au Chocolat, which means chocolate Royal.

Origin of Royal cake

The origin of the Royal cake is unknown, but it is one of the most popular cakes in France. The dessert is also called “Versaillais” or “Trianon.” According to one of the versions, the cake was named after a village Trianon near Versailles. It is usually made in a round or rectangular form.

The Royal cake looks sophisticated, but it is easy to make. There is a couple of ingredients that you may be unfamiliar with. They are crepes Gavottes and hazelnut praline paste, but I will guide you where to buy and what alternatives to use in the recipe.

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 that is 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 that is based on whipping cream. Yes, three simple ingredients (chocolate, whipping cream, and milk) result in a dangerously addictive and delicious chocolate mousse.

How to decorate Royal chocolate cake

The most popular way to decorate the cake is to coat it with a chocolate glaze. The application of cocoa nibs at the base of the dessert is optional.

Another way of decoration is 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.

The easiest way to decorate Royal cake is to sprinkle the sides of the cake with chocolate shavings and to dust the top with cocoa powder.

Why this mousse chocolate cake recipe works

1. The Royal chocolate cake recipe is straightforward and easy enough to make;
2. The chocolate taste and flavor of the cake are the best in this dessert: it is worth devoting your time for the pleasure of the mouth!
3. The freezing option of the cake is at its best: the dessert can be frozen for a few weeks. So, it becomes evident that it is one of the best cakes for a homemade cake business.
4. The top of the dessert is perfect for decorations of your choice.

Ingredients

Here is a quick overview of what ingredients you will need. Follow the full recipe below for detailed 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 a 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 the 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: use egg whites at room temperature.

Sugar: the recipe calls for granulated white sugar.

Icing sugar: make it yourself with a coffee grinder or use 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 the one 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 (60ml) of cold water.

Almond flour, hazelnut flour/meal.

How to make Royal cake step by step

To make the dacquoise, preheat oven to 335 F/170 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 with the 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 in 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). Transfer the mousse in a pastry bag with a plain tip.

To assemble the cake, seal one side of an 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 on the sides of the ring (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 in 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 F/30 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 on a cake board with the use of two metal spatulas. Place the cake in the fridge to thaw for 3 to 4 hours.

Expert tips

• Do not over whisk egg whites while 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 the excess with a single pass over the top of the cake to avoid making marks.
• Store the decorated cake for 2 to 3 days in the fridge.
• Take the dessert out of the fridge about 20 minutes before tasting (the cold temperature alters the taste of chocolate).

Frequently Asked questions

Can you make the Royal cake in advance?

Yes, make this dark chocolate mousse cake one or more days in advance and keep it frozen. Decorate the cake on the day of serving.

How to freeze Royal cake

Wrap the cake in a plastic film well to prevent the absorption of freezer odors. Keep the cake frozen for up to two to three weeks. On the day of serving, decorate the cake and let it thaw 3 to 4 hours in the refrigerator.

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The nutritional information has been calculated using an online recipe nutrition calculator and is intended for informational purposes only and should be used as a general guideline. If the nutrition information is important to you, you should independently verify it using your preferred tool. 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.