Chocolate Royal Cake with Hazelnut Almond Dacquoise

Chocolate royal cake, aka Trianon cake, is a wonderful French chocolate entremets. It is composed of a nut meringue (hazelnut almond dacquoise), a praline crunch layer and a decadent chocolate mousse.

An entremets cake is a broad term that describes a cake composed of several layers with varying textures and flavors. The key component is generally a mousse.

This cake does take a little bit of time to prepare. But I chose the easiest version possible so that anyone can make it. We’ll be making an easy chocolate mousse without eggs or gelatin. And we’ll skip the chocolate mirror glaze and simply dust the top with cocoa powder.

Let me briefly walk you through the process so you have an idea of what we’ll be doing today.

General Overview

1. Prepare the dacquoise. Let it cool down at room temperature.
2. Make the praline crunch.
3. Cover the dacquoise with praline crunch and refrigerate it.
4. Make the chocolate mousse.
5. Assemble the cake and refrigerate it until set.
6. Unmold, dust with cocoa powder and enjoy!

What Is Dacquoise?

The dacquoise, pronounced “Da-kwaz”, is a nut meringue that is crispy on the outside and has a chewy, moist center.

To make a dacquoise, a French meringue (egg whites and sugar) is first prepared. Ground nuts are then very gently incorporated into the batter. The dacquoise is generally gluten free although some recipes might include flour to yield a spongier and more flexible texture. Sometimes cornstarch is added, to absorb the humidity.

The dacquoise can be piped into disks or evenly spread on a baking sheet. The desired shapes can then be cut and used in entremets and layer cakes.

Tip: The thickness of the dacquoise should be about 1 cm (0.4 inch), for a crispy exterior and a chewy interior. If the dacquoise is too thin, there won’t be much contrast in texture.

Some people also use the term “dacquoise” to describe a layer cake which is composed of nut meringue and buttercream or whipped cream.

Dacquoise Ingredients

• Egg whites: Room temperature eggs, ideally at a temperature of about 21°C (70°F), will whip up faster. Make sure the bowl is free of any fat residues or you’ll have trouble whipping the egg whites. You can wipe off the mixing bowl with vinegar before using it. We discussed what happens when you whip egg whites and what affects the stability of meringues when making French meringue.

• Sugar: Other than adding sweetness, the sugar will contribute to the chewy center of the dacquoise. But it will also be responsible for the crispy exterior. The more sugar there is in the recipe, the crisper the dacquoise will be. Some bakers also like to dust powdered sugar on top of the dacquoise for even more crispiness. This can be done before baking it, or a few minutes before the end of the baking time.

Tip: Dust the dacquoise with powdered (icing) sugar for a crispy exterior.

• Nuts: The nuts will add a wonderful flavor to the meringue. We’ll be making the dacquoise with almonds and hazelnuts today. But you can try it out with pistachios, walnuts, or even coconut. We’ll be using 50 g (1.8 oz.) of nut flour for 60 g (2.1 oz.) of egg whites, so about 83% of the weight of the egg whites. But according to Corriher¹, this amount can range anywhere from 40% to 110%. Generally, the more nuts are used, the heavier the dacquoise will be.

Praline Crunch Ingredients

• Almond hazelnut praline paste: You can use store-bought or homemade praline paste. If you’re making it yourself, you can prepare it ahead of time and keep it in the fridge. The recipe for the homemade version will be enough for two chocolate royal cakes. And you’ll have some leftover to enjoy with a spoon!

• Milk chocolate: The amount used in the praline crunch is quite small. But I would still recommend couverture chocolate which isn’t as sweet as regular milk chocolate.

• Puffed rice or crepe dentelle cookies (gavottes): Traditionally, the crunchy layer is made with gavottes. But they can be very hard to come by, depending on where you live. I simply use puffed rice (Rice Krispies). But you can also use crushed corn flakes if you don’t have anything else. The cake won’t feel as fancy with corn flakes but kids will devour it within seconds!

Chocolate Mousse Ingredients

The chocolate mousse of a royal cake is traditionally made with pâte à bombe. You can also make the mousse from crème Anglaise. These two types of mousse might be practical to use up the egg yolks leftover from the dacquoise. But today I chose to make an easy, eggless chocolate mousse.

• Chocolate: I love to use a combination of dark chocolate (65% cocoa) and milk chocolate (40% cocoa). The dark chocolate will help the mousse set and will add a deep chocolate flavor. The milk chocolate will soften the flavor and sweeten the mousse. Use couverture chocolate which has a higher amount of cocoa butter, essential in helping the mousse set properly. Couverture milk chocolate is also less sweet than regular milk chocolate.

• Milk: We’ll be adding hot milk to the melted chocolate to make a chocolate ganache base. This will make it much easier to combine with the whipped cream.

• Heavy cream: You should ideally use cream with a fat content of 35%. But definitely not less than 30% as it won’t whip. The cream should be very cold so that it whips easily. In case you missed it, head over to the sweetened whipped cream post to read all the tips for whipping cream.

Okay, are you ready to make the cake?

Hazelnut Almond Dacquoise

A meringue doesn’t wait and will start to deflate if it’s not baked quickly enough. So let’s start by preparing everything we will need before making the dacquoise.

Basic preparation

• Preheat the oven to 170°C (338°F, conventional setting).
• Line a baking sheet with parchment paper. Optional: Draw an 18 cm (7 inch) circle on parchment paper, to use as a guide. Flip the paper so that the ink is on the other side and place it on the baking sheet.
• Place a piping bag (no piping tip needed) in a large glass. Don’t cut the tip off the bag yet. If you don’t want to pipe, you can skip this. You’ll simply spoon the dacquoise onto the parchment paper.

Mix the nuts and powdered sugar

In order to get finely ground nuts, it’s best to process them with powdered sugar. The sugar absorbs part of the oil released by the nuts. So mixing the nuts with sugar will allow you to mix for longer before getting nut paste!

• Process the almonds, hazelnuts and about half of the icing sugar until finely ground. Don’t mix for too long or the nuts will start to get oily.

• Sift through a coarse strainer over a large plate (or parchment paper).
• Return the large pieces of nuts (that are on the strainer) to the food processor bowl.
• Add the remaining icing sugar and process once more.
• Sift over the previous batch of ground nuts. Depending on how powerful your food processor is, you might still end up with some larger pieces of nuts on the strainer. As long as they aren’t too large, just add them to the sifted nuts without processing a third time.
• Set aside while you prepare the meringue.

Prepare the French meringue

• In a clean bowl, free of any fat residues, start whipping the egg whites on low speed. Tip: Wipe off the bowl with vinegar before using it to get rid of any fat. And avoid using a plastic mixing bowl.
• Once the eggs are foamy, start adding the granulated sugar slowly.

• When you’ve added all the sugar, increase the speed to medium-high. Keep beating just until stiff peaks form and the sugar has fully dissolved. The meringue should look smooth and glossy. Note: The whipped eggs shouldn’t be too stiff or you’ll have troubling folding in the nuts.

Add the nuts to the meringue

• Using a spatula, gently fold in the nut mixture in 3 additions. Be careful not to deflate the meringue. Only mix as much as needed.

Bake the nut meringue

• Pipe the dacquoise into a circle, starting from the center and moving outwards in a circular motion (like a snail!). Or simply spoon the dacquoise onto the paper and using a spatula, gently spread it to an even thickness of about 1 cm (0.4 inch). Leftover dacquoise: You probably won’t need all the dacquoise for an 18 cm (7 inch) circle. So you can pipe small nut meringues as well, to enjoy before the cake is served!
• Bake in the middle of the oven for 15-18 minutes, or until lightly golden and no longer sticky to the touch.
• Remove from the oven. Set aside to cool down (at room temperature) before making the praline crunch. Don’t try to remove the dacquoise from the parchment paper while it’s hot or it might tear.

Almond Hazelnut Praline Crunch

• Place the milk chocolate in a medium-sized bowl. Heat in the microwave in 10 second increments, stirring in between, until fully melted.

• Mix in the almond hazelnut praline paste, until fully combined.

• Add the puffed rice to the praline mixture. If using crepe dentelle cookies or corn flakes, crush them first with your hands or a rolling pin.
• Stir with a large spoon until completely coated.

The puffed rice is coated in fat (melted chocolate and nut paste), shielding it from liquids. It will stay crispy for quite some time.

• Cut an 18 cm (7 inch) circle into the dacquoise using a cake ring (or a knife).
• Spoon the praline crunch onto the dacquoise and spread it evenly. I do this without removing the cake ring. The cake ring makes it easier to spread the crunch near the edges. But you can skip it if you don’t have one.
• Refrigerate while you prepare the mousse.

Easy Chocolate Mousse

• Whip the cold heavy cream to soft peaks. Cover and refrigerate while you prepare the chocolate. Don’t whip the cream to stiff peaks or you’ll have trouble combining it with the chocolate. Optional: Pour the heavy cream into the mixing bowl and refrigerate it, along with the beaters for about an hour before starting.

• Place the coarsely chopped chocolate in a microwavable bowl. Heat in the microwave in 20 second increments, stirring in between, just until fully melted. You can heat the chocolate using a double boiler if you prefer.

• Heat the milk and pour over the melted chocolate in 3 additions. Gently stir using a large spoon or a spatula. Start by making circles in the center of the bowl and move outwards. The milk shouldn’t be too hot or the chocolate will become thick and grainy.

• When the chocolate is at a temperature of about 45-50°C (113-122°F) or is slightly warm to the touch, add a little bit of whipped cream to the chocolate to lighten it.

Tip: If the chocolate is too hot, it will deflate the cream. If it’s too cold, it will solidify and yield a grainy texture. Reheat it in the microwave if needed before adding the whipped cream.

• Add the chocolate mixture to the whipped cream and gently fold it in, being careful not to deflate the whipped cream.

Assembling The Chocolate Royal Cake

• Place the dacquoise with praline crunch on a platter (remove the cake ring if you used one).

• Place a 20 cm (8 inch) cake ring around the dacquoise and center it. Line the cake ring with acetate sheet or parchment paper. This will make it much easier to unmold the cake later on.

Tip: Wait for the chocolate mousse to set for just a few minutes if needed before assembling the cake. If it’s too runny, the mousse might leak out of the cake ring.

• Start by piping the chocolate mousse in the gap around the dacquoise. The piping bag will make it easier to fill the small gap evenly. But you can skip it if you don’t want to use one and use a spoon instead.
• Keep piping a little more on the sides of the cake, to make sure you get a smooth surface when you unmold.

• Pipe (or spoon) the remaining mousse on top of the praline crunch. Smoothen with a spoon or spatula as much as possible. Cover loosely (without touching the mousse) and refrigerate for a few hours or until completely set.
• Carefully remove the cake ring and the acetate sheet. Smoothen the sides of the mousse with a spatula, if needed.
• Dust with cocoa powder if desired and enjoy!

Troubleshooting Dacquoise

The dacquoise is too runny

• The meringue was too soft: You should beat the egg whites to stiff peaks. If you don’t whip them enough, the dacquoise won’t hold its shape well when you try to pipe it.

• The nut flour wasn’t folded in properly: The nut flour should be added very carefully with a spatula, to avoid deflating the meringue.

• The dacquoise wasn’t baked immediately: Make sure your oven is preheated. Once the dacquoise is ready, it should quickly go into the oven.

• Deflated during piping: If you press too much on the piping bag, you risk deflating the dacquoise. If you’re not comfortable piping the dacquoise, skip it. Simply spoon it onto a piece of parchment paper.

The dacquoise is too soft or sticky

• Underbaked: If you remove the dacquoise from the oven too soon, not enough water will have evaporated. The dacquoise won’t have its characteristic crisp exterior. Try baking it for longer next time or increasing the oven temperature a little.

• Still warm: If you try to remove the dacquoise from the parchment paper too soon, the bottom might be too sticky. The dacquoise will easily tear and fall apart. Wait for it to cool down before trying to remove it. I prefer to refrigerate with the praline crunch before attempting to peel the parchment paper off.

• Humidity: If your baked dacquoise was crisp but softened at room temperature or became sticky, it’s most likely due to humidity. Nut meringues contain a lot of sugar which is hygroscopic and will attract water. Avoid baking on humid days if possible.

The dacquoise deflated

• Underbaked: The nut meringue will slightly deflate when you take it out of the oven. But if it deflates a lot, you probably need to bake it for longer.

And that’s it! I hope you won’t be intimidated by the long instructions. This cake isn’t hard to make and is really worth the time you put in.

More French Desserts

• Paris-Brest
• Strawberry charlotte cake
• Hazelnut raspberry financiers
• Fraisier with mousseline cream

Bibliography

¹Corriher, S. O. (2008). Bakewise: The Hows and Whys of Successful Baking. Scribner.