Dark Chocolate Mousse Cake

Three layers and three textures of dark chocolate goodness in one indulgent dark chocolate mousse cake!
My love affair with chocolate since the beginning
Since I can remember, I love chocolate!
I was a lucky child because there was always a chocolate cake with fudge in our kitchen. This fact made me quite popular at school and with neighbourhood friends, who used to pop by to hang out and enjoy a piece of soft, moist and fudgy chocolate cake.
The better chocolate – dark
Dark chocolate has less sugar than white and milk chocolate therefore, I only eat dark chocolate. I love to have a couple of pieces of 99% cacao chocolate, which is quite bitter but satiates my cravings for sweets. However, for desserts, I like to use 70% cacao chocolate. It is dark and for my taste, it has the right amount of sugar.
The inspiration for this dark chocolate mousse cake
Some days ago, I went to one of my favourite Italian restaurants in London and this time we ordered the chocolate mousse cake instead of the tiramisu – for a change.
The chocolate mousse cake was amazing, fresh and creamy on the inside, with a beautiful chocolate sponge cake as a base. This delight inspired me to make my version of this cake. I already have a great French chocolate mousse recipe on the blog. I also have a great Peruvian chocolate sponge cake recipe – the one they used to bake at home when I was a child. I decided to add a third layer, a dark chocolate ganache, which I learned how to make at Le Cordon Bleu Paris. So, this succulent cake has three recipes that result in a fresh yet indulgent chocolatey experience.
Dark chocolate mousse cake recipe in four easy steps
Use a 30cm diameter round mould
Step 1 – Make the chocolate sponge cake (about 1.5 cm high)
Ingredients:
¾ cup whole wheat flour
½ cup brown sugar
¼ tablespoon baking powder
¼ cup unsweetened cocoa powder
½ heaping teaspoon baking soda
½ teaspoon salt
1 egg
½ cup milk
½ tablespoon white vinegar
½ cup vegetable oil (grapeseed oil is a good neutral choice)
¼ teaspoon vanilla essence
Instructions:
- Preheat the oven at 180 degrees C or 350 degrees F.
- Grease a round mould of 30 cm diameter and cover the bottom with baking paper.
- Sift the flour 3 to 4 times. This will add air to the mix and will result in a lighter sponge cake.
- Pour the white vinegar into the milk and let sit.
- Sift once into the bowl with flour, the other dry ingredients: brown sugar, baking powder, unsweetened cocoa powder, baking soda and salt.
- Add the vegetable oil to the sifted dry ingredients and mix well with a spatula until it becomes a uniform batter.
Dry sifted ingredients Oil mixed into dry ingredients
- Add the milk with vinegar and mix.
- Add the egg and mix.
- Finally, add the vanilla extract and mix well.
- Pour the mixture in the round cake mould and place it in the middle of the preheated oven at 180 degrees C or 350 degrees F.
Greased mould with baking paper on the bottom Chocolate sponge cake ready
- Bake for 10-15 minutes. Start checking after 10 minutes.
- Let cool in the mould for five minutes.
- Carefully unmould and put on a rack to cool down while you make the French chocolate mousse.

Step 2 – Make the French chocolate mousse
Ingredients:
200 gr good quality dark chocolate; I used 70% cacao
8 eggs, yolks and whites separated
¼ cup non-dairy milk or regular milk if you prefer. I used oat milk.
Instructions:
- Melt chocolate and non-dairy milk in ‘bain-marie’ or water bath in low heat. The water should be simmering and not boiling. The water shouldn’t touch the base of the bowl on top.

- When melted, remove from the heat and introduce the egg yolks one by one and mix. The result should be homogeneous and shiny.

- Beat the egg whites to stiff peaks.
- Add egg whites to the chocolate little by little and mix delicately with a spatula.

Step 3 – Make the dark chocolate ganache
Ingredients:
200 gr cream
200 gr good quality dark chocolate; I used 70% cacao
¼ teaspoon vanilla extract
Instructions:
- Boil cream and vanilla.
- Place chocolate pieces in a bowl.
- Add half of the boiling mix to the chocolate and wait until it melts.

- Use a whisk to mix the chocolate only in one spot.
Chocolate pieces, boiling cream and a whisk in action Mixing ganache with a whisk in one spot
- Add the rest of the cream and mix.
- For the perfect texture, use an electric hand mixer to make a perfectly homogeneous ganache.

- Let cool in a tray until soft and creamy.
Step 4 (final step) – Assemble the chocolate mousse cake
- Remove the baking paper from the sponge cake.
- Once the chocolate sponge cake has cooled down cut the dome (if any) to have a straight sponge cake layer.
- Place the sponge cake back into the round mould and lightly press it down to. Have an even layer.
- Pour the chocolate mousse on top and tap the mould a few times to get rid of any air bubbles.

- Cover the top of the mould and refrigerate overnight.
- Unmould the cake and pour the chocolate ganache on top allowing it to fall a little bit on the sides.
- Make the ganache before decorating and serving the cake. If you make it in advance, heat it in ‘bain-marie’ or water-bath and cool it down until you get a good texture to pour on top of the cake.
- Decorate with chocolate shavings or unsweetened cocoa powder (optional).

Tips:
- Serve the cake chilled, right out of the fridge to avoid the sponge cake base become too humid.
- Make sure the ganache is cool but not too cold, therefore, solid. The perfect texture will be a shiny and thick creamy chocolate ganache.

Find more sweet recipes here