This post was sponsored by Valrhona USA.
Today is national chocolate cake day, so why not treat yourself with a 100% chocolate cake?
I decided to go with different textures and different chocolates.
For textures, there will be a dark chocolate sponge that will melt in your mouth, a milk and hazelnut crémeux, and a dark chocolate mousse. All of this is covered with a dark chocolate mirror glaze.
For the mousse, the mirror glaze, and the sponge, I opted for Caraibe, a 66% dark chocolate with has a hint of bitterness and fruity notes.
For the crémeux, I used Azelia, a 35% chocolate I really love because it’s a milk chocolate that contains actual hazelnuts! It’s so good that I keep stealing from chocolate bag (too) often. The crémeux brings a nice nutty flavor and sweetness to this cake which balances out the slight bitterness of the mousse. This combination is heavenly!
The mirror glaze and the chocolate leaves (method in a blog post do come) are what make this cake stand out.
Tips to succeed :
Sponge cake:
Melt your chocolate with butter in a double boiler and make sure to add your egg yolks while your chocolate and butter are still hot!
Make sure to add your egg whites into your egg yolks gently for the sponge cake. There is no baking powder in the cake as the rise will come from the meringue made with egg whites.
As soon as it is baked, wait for a few minutes until it cools down before putting saran wrap on top of it. This will retain the humidity of the cake.
Cremeux and mousse
For both the crémeux and the mousse, you have to cook the egg yolks at 179-183°F (82-84°C). If you do not have a thermometer, cook your eggs while always stirring, stop when the mixture becomes thick, and start to coat your spatula. It should look like this.
It’s always better, if you have one, to use a immersion blender to mix your chocolate with your cooked eggs. This will make a perfect emulsion (perfect mix that will not separate)
Mousse
Don’t overwhip the cream, you should get very soft peaks when you incorporate whipped cream into your melted chocolate. That will make for a very light and airy mousse.
Start by incorporating ¼ of the whipped cream with a whisk then the rest with a spatula. That will make the mix easier to do.
Use the mousse immediately after making it! f you wait it will be very difficult to fill your mould and the texture will not be optimal.
Mirror glaze
The mirror glaze must be applied to a frozen mousse cake. Make sure that your cake has been in the freezer for at least 5-6 hours.
The mirror glaze must be at 75°F (24°C) when you apply it to your mousse cake. Make sure to mix it with an immersion blender before pouring it on your cake. You can freeze the remaining for weeks!
As always, the main key to succeeding at this mousse cake is to take your time and plan in advance. You don’t have to do all the elements of this dessert the same day. You can make the crémeux and freeze it for days until use. Same for the sponge. The only thing that has to be done right before use is the chocolate mousse. I recommend you to do this mousse cake in two days to pace yourself.

100% chocolate cake
Equipment
- 18 cm large, 5 cm high cake ring or silicone mould
- 16 cm large and 2 cm high (or higher) cake ring
- 20 cm large cake pan
- hand mixer or stand mixer
- saucepan
- thermometer
- immersion blender
Ingredients
Milk chocolate Cremeux
- 170 g whipping cream (30%fat min.)
- 20 g egg yolks (1 yolk)
- 15 g sugar
- 120 g Azelia milk chocolate
Dark chocolate sponge
- 60 g butter
- 55 g egg yolks (4 yolks)
- 110 g egg whites (4 (whites)
- 60 g sugar
- 20 g flour
- 125 g caraibe chocolate
Dark chocolate mousse
- 100 g milk
- 100 g whipping cream (1)
- 40 g egg yolks (2-3)
- 30 g sugar
- 250 g Caraibe chocolate
- 400 g whipping cream (2)
Dark chocolate mirror glaze
- 290 g sugar (1)
- 120 g water (1)
- 90 g whipping cream
- 100 g water (2)
- 130 g sugar (2)
- 120 g dark chocolate caraibe
- 18 g Gelatin 200 bloom+ 108 g water for gelatin (3)
Instructions
Milk chocolate Cremeux
- In a small saucepan, bring whipping cream to a boil. In a bowl, whisk together egg yolks and sugar. Pour a 1/3 of hot whipping cream on egg yolks. Whisk and pour everything back to the saucepan. Cook on low heat while continuously stirring until it reaches a temperature of 84°C. Pour directly on Azelia milk chocolate chopped in small pieces. Whisk until chocolate is fully melted and integrated. Mix with an immersion blender to get a perfect emulsion. Pour in a 16 cm large mould and keep in the freezer 0°F (-18°C) until it hardens (at least 4h).
Dark chocolate sponge
- In a small bowl, melt dark chocolate with butter. Add egg yolks to melted chocolate and whisk. Whip egg whites with sugar to soft peaks and gently add them, little by little to the yolk+chocolate mix with a spatula. Add flour previously sifted. Bake into a20 cm round baking pan for 12 min at 200°C. Wait until it cools down. Cut it to 16 cm with a ring. Wrap it and keep it in the freezer 0°F (-18°C) until use.
Dark chocolate mousse
- In a small saucepan, bring milk and whipping cream (1) to aboil. In a bowl whisk together egg yolks and sugar. Pour a 1/3 of hotmilk+whipping cream on egg yolks. Whisk and pour everything back to the saucepan. Cook on low heat while continuously stirring until it reaches a temperature of 84°C. Pour directly on Caraïbe chocolate chopped in small pieces and whisk until chocolate is fully melted and integrated. Mix with an immersion blender to get a perfect emulsion. Whip whipping cream (2) to soft peaks. Add ¼of whipped cream to the chocolate mixture with a whisk. Add the rest of whipped cream gently with a spatula. Use immediately.
Upside down entremets assembly
- Pour the chocolate mousse on your mold and fill with it to1/3 of the mould. Make sure to apply mousse on the sides of the mould as well. Put the frozen milk chocolate crémeux in the middle. Pour again chocolate mousse on top of the crémeux up to ¾ of the mold. Finally, add the dark chocolate sponge and push it down until the mousse entirely fills the mould. Leave in the freezer 0°F (-18°C) for at least 6 hours.
Dark chocolate mirror glaze
- Whisk 108 g of water (3) with gelatin and keep in the fridge for 20 minutes. In a small saucepan, Cook water (1) with sugar (1) until it reaches 230°F (110°C) to make a syrup, remove it from heat. In another saucepan, bring to a boil whipping cream, water (2), and sugar (2) and add syrup to it. Bring everything to a boil before adding gelatin. Pour onto dark chocolate chopped in small pieces. Mix with an immersion blender to get a perfect emulsion. Cover with saran wrap. Let it rest in the fridge for at least6 hours. Heat up to (75°F) 24°C in a double boiler or microwave and mix with an immersion blender before using it. Unmold your frozen entremets, place it on a flat surface such as a metal grid to allow for the glaze to flow on the outsides of the mousse cake. Immediately pour your glaze at (75°F) 24°C directly on the mousse cake. Immediately use a spatula to remove the surplus glaze on top of the cake. Once the glaze stops dripping, remove the glaze at the bottom edge of the cake. Place it on a cake board and allow it to thaw in the fridge for at least 8hours. For optimal taste, remove it from the fridge 30 minutes before serving. Otherwise, always leave it in the fridge and eat it within 2 days.