Chocolate Mousse Layer Cake (Printer-Friendly)
A decadent dessert featuring a layered chocolate base, creamy mousse, and smooth ganache finish.
# What You'll Need:
→ Chocolate Cake Base
01 - 3/4 cup all-purpose flour
02 - 1/4 cup unsweetened cocoa powder
03 - 1/2 teaspoon baking powder
04 - 1/4 teaspoon salt
05 - 1/2 cup granulated sugar
06 - 2 large eggs
07 - 1/3 cup whole milk
08 - 1/4 cup vegetable oil
09 - 1 teaspoon vanilla extract
→ Chocolate Mousse
10 - 7 oz dark chocolate (60–70% cocoa), chopped
11 - 3 large eggs, separated
12 - 1/4 cup granulated sugar
13 - 1 1/4 cups heavy cream, cold
14 - 1 teaspoon vanilla extract
15 - Pinch of salt
→ Chocolate Ganache
16 - 3.5 oz dark chocolate, chopped
17 - 1/3 cup heavy cream
# How to Make It:
01 - Preheat the oven to 350°F. Line a 9-inch springform pan with parchment paper, then lightly grease the sides.
02 - In a medium bowl, sift together the flour, cocoa powder, baking powder, and salt.
03 - In a separate bowl, whisk the sugar and eggs until pale and thick, about 2 minutes. Add milk, vegetable oil, and vanilla extract; mix to combine.
04 - Gradually fold the dry ingredients into the wet mixture until smooth.
05 - Pour the batter into the prepared pan and smooth the surface. Bake for 20 to 25 minutes or until a toothpick inserted in the center comes out clean. Allow to cool completely in the pan.
06 - Melt the 7 oz of dark chocolate in a heatproof bowl over simmering water, stirring until smooth. Remove from heat and let cool slightly.
07 - Whisk the egg yolks with half of the sugar (2 tablespoons) until creamy. Fold this into the melted chocolate.
08 - In a clean bowl, beat the egg whites with a pinch of salt until soft peaks form. Gradually add the remaining sugar and beat until stiff peaks form.
09 - Whip the cold heavy cream along with vanilla extract until soft peaks form.
10 - Gently fold the whipped cream into the chocolate mixture, then fold in the beaten egg whites in two additions until fully incorporated and aerated.
11 - Spread the mousse evenly over the cooled cake base in the pan, smoothing the top. Cover and chill for at least 3 hours to set.
12 - Heat the 1/3 cup heavy cream in a small saucepan until it just begins to simmer. Remove from heat, add the chopped dark chocolate, and let sit for 2 minutes. Stir until smooth and glossy. Allow to cool slightly.
13 - Pour the ganache over the chilled mousse layer and spread evenly. Refrigerate for at least 1 hour until the ganache is firm.
14 - Run a knife around the edge of the cake to loosen it from the pan. Remove the springform ring, slice, and serve chilled.
# Expert Advice:
01 -
- The three layers give you everything at once—tender cake, silky mousse, and glossy chocolate ganache in every bite, like a complete chocolate experience on your fork
- It looks absolutely stunning when you unmold it, which means people think you spent all day in the kitchen even though most of the work is just waiting for it to chill
- The mousse is light enough that even after a big dinner, you can eat a slice without feeling like you've swallowed a brick of chocolate
02 -
- The most common failure happens when the mousse breaks as you fold—usually because the chocolate was too warm or too cold when you added the eggs. If the chocolate is warm, it will scramble the yolks. If it's cold, the texture becomes grainy. Aim for lukewarm—cool to touch but not cold.
- Those egg whites are non-negotiable for success. They're what makes this mousse airy instead of dense. Some people worry about raw eggs in the mousse, and that's fair—use pasteurized eggs from your store if that's a concern for you or your guests.
- Chill times aren't suggestions. A mousse that hasn't set properly will collapse when you unmold it, and nobody wants to serve a 'cake' that's more puddle than structure.
03 -
- Keep everything clean and dry as you work, especially your bowls and beaters. Even a tiny bit of egg yolk in your egg white bowl will prevent them from whipping. A drop of water in your whipped cream can turn it into butter before you know what happened.
- Temperature is everything in this recipe. Room-temperature eggs mix better and incorporate more air. Cold cream whips better and holds its shape longer. A lukewarm chocolate base won't scramble your eggs or seize when you fold. A cool but not cold ganache spreads beautifully and sets with a glossy finish.