Dreamy Decadent Chocolate Mousse Cake Recipe
Prep Time:
9 hours
Cook Time:
20 minutes
Servings:
12 Slices
Ingredients
  • 1 teaspoon butter, for greasing pan
  • ½ cup caster sugar
  • 3 large eggs, room temperature
  • ⅓ cup all-purpose flour
  • 2 tablespoons cocoa powder
  • ½ teaspoon baking powder
  • Pinch of salt
  • 1 ½ cups heavy cream, divided
  • ½ teaspoon vanilla extract
  • 2 teaspoons gelatin powder
  • 15 ounces dark chocolate
  • 1 tablespoon butter
  • 3 large eggs, yolks and whites separated
  • 4 tablespoons caster sugar
  • 5 ounces dark chocolate
  • ⅔ cup heavy cream
Directions
  1. Preheat the oven to 400 F.
  2. Grease and line an 8-inch cake tin with baking paper.
  3. In a stand mixer, beat together the sugar and eggs for 6 to 7 minutes until the mixture is thick and pale.
  4. In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt.
  5. Sift the dry ingredients into the wet ingredients, and gently fold.
  6. Transfer the cake batter to the prepared tin.
  7. Bake the cake batter for 15 minutes until it springs back to the touch, then set aside to cool completely.
  8. Once cool, remove the cake from the tin and wrap a clear cake collar around it before placing it back into the cake tin.
  9. To begin the mousse, whip together ¾ cup cream with the vanilla extract, then place in the fridge until needed.
  10. Mix the gelatin powder with 4 teaspoons water, and set aside 5 minutes.
  11. Add the dark chocolate, remaining ¾ cup cream, and the tablespoon of butter to a bowl set over a saucepan of hot water.
  12. Mix the chocolate and other ingredients until they are melted and combined.
  13. Remove from the heat and whisk in the egg yolks.
  14. Stir in the gelatin powder mixture and then set to one side.
  15. Add the 3 egg whites to a stand mixer and whisk on high for 1 to 2 minutes until peaks form.
  16. Feed the 4 tablespoons of sugar into the egg whites and keep beating until the sugar has completely dissolved.
  17. Gently fold the egg white mixture into the cooled chocolate mixture in two batches.
  18. Fold the chilled whipped cream from the fridge into the chocolate mixture.
  19. Pour the chocolate mousse onto the cake base in the prepared tin.
  20. Place the cake into the fridge to set for at least 8 hours, or overnight.
  21. For the ganache layer, break up the chocolate into little pieces in a heatproof bowl.
  22. Heat the cream in the microwave on a high heat for 1 minute, until it is hot but not boiling.
  23. Pour the hot cream over the chocolate and whisk until the mixture is smooth and glossy.
  24. Pour the ganache over the top of the mousse layer, and place in the fridge to set for 10 minutes.
  25. If you wish, decorate the chocolate mousse cake with frosting or extra sprinkles, or serve as-is.