Chocolate Mousse Cake

This elegant chocolate mousse cake features a rich chocolate cake base topped with a light, creamy chocolate mousse and finished with a silky chocolate ganache. It’s perfect for birthdays, holidays, or any special occasion.

Prep Time: 35 minutes
Bake Time: 25–30 minutes
Chill Time: 4 hours
Total Time: About 5 hours 5 minutes
Servings: 12

Ingredients

Chocolate Cake Layer

• 1 cup (125 g) all-purpose flour
• ½ cup (50 g) unsweetened cocoa powder
• 1 teaspoon baking powder
• ½ teaspoon baking soda
• ¼ teaspoon salt
• ¾ cup (150 g) granulated sugar
• 1 large egg
• ½ cup (120 ml) milk
• ¼ cup (60 ml) vegetable oil
• 1 teaspoon vanilla extract
• ½ cup (120 ml) hot coffee or hot water

Chocolate Mousse

• 8 oz (225 g) semisweet chocolate, finely chopped
• 2 tablespoons unsalted butter
• 2 cups (480 ml) heavy whipping cream, divided
• 2 tablespoons powdered sugar
• 1 teaspoon vanilla extract

Chocolate Ganache

• 4 oz (115 g) semisweet chocolate, chopped
• ½ cup (120 ml) heavy whipping cream

Optional Garnishes

• Chocolate curls
• Fresh berries
• Cocoa powder
• Whipped cream
• Chocolate shavings

Instructions

Make the Cake

1. Preheat the oven to 350°F (175°C). Grease and line an 8-inch (20 cm) round cake pan.
2. In a bowl, whisk together the flour, cocoa powder, baking powder, baking soda, salt, and sugar.
3. Add the egg, milk, oil, and vanilla. Mix until smooth.
4. Stir in the hot coffee until the batter is thin and well combined.
5. Pour into the prepared pan and bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean.
6. Cool completely in the pan, then transfer to a serving plate or springform pan.

Make the Chocolate Mousse

1. Melt the chopped chocolate and butter together over a double boiler or in the microwave using 20-second intervals. Let cool until just warm.
2. Whip 1½ cups (360 ml) of the heavy cream with the powdered sugar and vanilla until soft peaks form.
3. Fold one-third of the whipped cream into the melted chocolate to lighten it.
4. Gently fold in the remaining whipped cream until no streaks remain.
5. Spread the mousse evenly over the cooled cake.
6. Refrigerate for 3–4 hours, or until set.

Make the Ganache

1. Heat the remaining ½ cup (120 ml) heavy cream until it just begins to simmer.
2. Pour it over the chopped chocolate and let sit for 2 minutes.
3. Stir until smooth and glossy.
4. Let the ganache cool for about 10 minutes, then pour it over the chilled mousse, spreading gently to the edges.

Finish

• Chill for another 30–60 minutes before removing the cake from the springform pan (if using).
• Garnish with chocolate curls, whipped cream, or fresh berries before serving.

Storage

• Refrigerator: Store covered for up to 4 days.
• Freezer: Freeze for up to 2 months. Thaw overnight in the refrigerator before serving.

Tips

• Use high-quality chocolate for the richest flavor.
• Make sure the cake is completely cool before adding the mousse.
• Chill the mixing bowl and beaters before whipping the cream for the fluffiest mousse.
• For clean slices, dip a sharp knife in hot water and wipe it dry between each cut.