Description
This Chocolate Mousse Cake is a rich, elegant dessert with a soft chocolate cake base, light and airy chocolate mousse, and a silky ganache topping. It’s perfect for birthdays, dinner parties, holidays, or any occasion when you want an impressive homemade dessert.
Ingredients
For the Chocolate Cake
- 1 cup all-purpose flour
- ¾ cup granulated sugar
- ¼ cup unsweetened cocoa powder
- ¼ cup black cocoa powder, sifted
- 1 teaspoon baking powder
- ½ teaspoon baking soda
- ½ teaspoon salt
- 1 large egg
- ½ cup whole milk
- ¼ cup vegetable oil
- 1 teaspoon pure vanilla extract
- ½ cup boiling water
- 1 teaspoon instant espresso powder, optional
For the Chocolate Mousse
- 4 large egg yolks
- ⅓ cup granulated sugar
- Pinch of salt
- 2 teaspoons pure vanilla extract
- 12 ounces semi-sweet chocolate, finely chopped
- 2 cups cold heavy whipping cream, divided
For the Ganache
- 4 ounces semi-sweet chocolate, finely chopped
- ½ cup heavy whipping cream
Instructions
Make the Chocolate Cake
- Preheat the oven to 350°F and butter a 9-inch springform pan. Line the bottom with parchment paper.
- Whisk together the flour, sugar, cocoa powders, baking powder, baking soda, and salt.
- Add the egg, milk, oil, and vanilla. Whisk just until combined without overmixing.
- Dissolve the espresso powder in the boiling water, if using, then pour it into the batter and gently whisk until combined.
- Pour the thin batter into the prepared pan.
- Bake for 20–25 minutes, or until a skewer inserted into the center comes out clean.
- Cool the cake in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.
- Level the top of the cake with a serrated knife.
- Clean and prepare the springform pan again, lining the bottom with parchment and the sides with a cake collar or parchment.
- Place the cooled cake back into the pan.
Make the Chocolate Mousse
- Place the egg yolks and sugar in a heatproof bowl and whisk together.
- Set the bowl over a pot of gently simmering water, making sure the bottom does not touch the water.
- Whisk constantly for about 10 minutes until the mixture thickens and reaches 160°F.
- Remove from the heat and whisk in the salt and vanilla.
- Add the chopped chocolate and allow it to begin melting.
- Heat ⅔ cup of the heavy cream until steaming and bubbling around the edges, but do not boil.
- Pour the hot cream over the chocolate mixture and whisk until smooth.
- Allow the chocolate mixture to cool completely to room temperature.
- Whip the remaining 1⅓ cups heavy cream to stiff peaks.
- Gently fold one-third of the whipped cream into the cooled chocolate mixture.
- Fold in another third, followed by the final third, mixing just until smooth and airy.
- Pour the mousse over the cake and smooth the surface.
- Refrigerate for at least 4 hours, or until completely set.
Make the Ganache
- Place the chopped chocolate in a bowl.
- Heat the heavy cream until steaming and bubbling around the edges without boiling.
- Pour the hot cream over the chocolate and let it sit for about 5 minutes.
- Whisk until smooth and glossy.
- Allow the ganache to cool slightly if it is too hot.
- Remove the chilled cake from the springform pan and peel away the parchment or cake collar.
- Pour the ganache over the top and spread evenly.
- Refrigerate for another 5–10 minutes before slicing and serving.
Notes
- Serve the cake well chilled for the cleanest slices.
- Use a sharp knife dipped in warm water and wiped dry between slices.
- Garnish with chocolate shavings, berries, cocoa powder, or whipped cream.
- Keep the cake refrigerated until ready to serve.
- Store leftovers in an airtight cake container in the refrigerator for up to 4 days.
- For the best texture, avoid leaving the mousse cake at room temperature for extended periods.
- You can prepare the cake a day ahead, making it an excellent dessert for entertaining.
- Freeze individual slices tightly wrapped for up to 1 month. Thaw them overnight in the refrigerator.