Chocolate Mousse Cake

Instructions

1. Prepare the cake base
   Preheat the oven to 180°C (350°F). Grease and line a 23cm springform cake tin. Melt 100g dark chocolate and 175g butter in a heatproof bowl set over simmering water. Remove from heat and stir in sugar. Allow to cool slightly, then beat in egg yolks and vanilla extract until smooth.
2. Finish the cake batter
   In a separate bowl, whisk egg whites until stiff peaks form. Sift the flour and cocoa powder together. Fold the flour mixture into the chocolate mixture, then gently fold in the egg whites until just combined, being careful not to knock out the air.
3. Bake the cake
   Pour the batter into the prepared tin and smooth the surface. Bake for 25-30 minutes until a skewer inserted into the center comes out with a few moist crumbs. Allow to cool completely in the tin on a wire rack.
4. Prepare the dark chocolate mousse layer
   Sprinkle 1 tbsp gelatin over 3 tbsp cold water and let stand for 5 minutes. Melt the remaining dark chocolate in a heatproof bowl over simmering water. Gently heat the bloomed gelatin until dissolved. Whip 150ml of cream until soft peaks form. Stir the melted gelatin into the chocolate, then fold in the whipped cream. Spread over the cooled cake and refrigerate for 1 hour.
5. Create the milk chocolate mousse layer
   Repeat the process with the milk chocolate: bloom 1 tbsp gelatin in 3 tbsp cold water, melt the milk chocolate, dissolve the gelatin, and fold into 150ml whipped cream. Spread this layer over the set dark chocolate mousse and refrigerate for another hour.
6. Finish with decoration
   Melt the white chocolate and drizzle over the top of the cake. Dust with cocoa powder. Refrigerate for at least 2 hours or overnight until completely set. Run a warm knife around the edge of the cake before releasing from the springform tin.