An easy chocolate mousse cake exclusively for chocolate lovers! This decadent chocolate dessert, inspired by the luscious French gâteaux, is the perfect way to celebrate a birthday or any special occasion. And the best part? With a simple step-by-step guide, both beginners and experienced bakers will find it a breeze to create this recipe.
Preheat your oven to 350°F (175°C).Grease two 8-inch (20 cm) cake pans and line them with parchment paper (if you don't own two 8-inch pans, use aluminum foil disposable cake pans or bake the cakes the one after the other).
Transfer the flour, the cocoa powder, the baking powder, the salt and the sugar in a medium bowl and mix well. Then, add the oil, the water/coffee, the eggs and the vanilla and mix with a whisk until you get a smooth mixture (it will be on the runny side).
Divide the cake batter evenly between the prepared pans (eyeball it or use a scale and pour 15oz / 425grams of batter into each pan).Bake for 35-37 minutes or until a toothpick inserted in the center of each cake comes out clean. Transfer the cakes on a wire rack and let them cool completely before frosting (no need to unmold them).
Make the syrup:
Transfer the sugar and the water to a small pot and boil until the sugar is dissolved. Add the brandy, stir well and chill in the fridge.
Make the chocolate mousse:
Transfer the milk and the cocoa powder to a small pot and stir until the cocoa powder is completely dissolved. Heat over medium heat until almost boiling, remove from the heat and add the chopped chocolate and the honey. Stir until the chocolate melts completely, then let it cool until lukewarm.
Whip the heavy cream with a hand mixer (or a stand mixer with the whisk attachment) until stiff peaks form. Then, take a small amount of the whipped cream and mix it with the melted chocolate. After that, pour the chocolate mixture into the bowl with the whipped cream and gently fold with a spatula until combined and you can no longer see white streaks. Refrigerate the mousse until needed.
Assemble the cake:
Transfer one cake layer onto a serving plate with the bottom side facing up (it will absorb the syrup better this way). Drizzle the surface with ¼ cup (60 ml) of syrup. Then, spread ⅓ of the chocolate mousse filling over the surface of the cake (don't go all the way to the edges, because the mousse will spread further by the weight of the top layer).
Put the second cake on top (bottom side facing up), and drizzle with ¼ cup (60 ml) of syrup. Using an off-set spatula, cover the top and the sides with the remaining frosting/mousse.Leave the frosting smooth or create swirls and peaks for that homemade touch. Optionally, garnish with chocolate curls, cocoa powder, icing sugar or fresh fruit such as raspberries. Add white chocolate shavings for contrast.
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Notes
Consider making this chocolate cake one day ahead, since it is even better the next day when all the flavors have blend together and the syrup is evenly distributed.
This chocolate mousse cake needs to be refrigerated if not consumed right away. Take it out of the fridge 30-60 minutes before serving for the best texture.
To eliminate the alcohol from the syrup, add the brandy from the start and boil the syrup for 2 minutes. Otherwsie, you can also omit it.
For the chocolate: You can use couverture, bittersweet or semi-sweet chocolate. As long as it's real chocolate (no chocolate melts) and it says that it's 55% cocoa or more, you're good to go.
Only for experienced bakers: When making the chocolate mousse (which is basically a whipped chocolate ganache), you can increase the milk to one cup (240 grams) and the heavy cream to 1 ⅔ cups (400 grams). Also, you can beat the cream to soft peaks (consistency similar to yogurt) instead of stiff peaks. This will result in the following:
Pros: the chocolate mousse will have a creamier, softer and fluffier texture.
Cons: it may be harder to frost the cake (the mousse should be cold) and it will not hold as well at room temperature, especially on a hot day.