Soften gelatin in cold water. Heat coconut milk and cream. Whisk yolk with sugar, temper with hot liquid, and cook to 83°C. Add gelatin and blend with Malibu. Pour into a cling film-lined rectangular frame. Freeze until partially set.
Whip egg whites with powdered sugar to stiff peaks. Fold in yolks, then sift in cocoa and starch. Fold gently. Spread on lined tray and bake at 180°C for 10–12 mins. Cut two rectangles using the same frame.
Coconut Crunch
Melt milk chocolate and butter. Mix in crushed wafers and coconut. Spread over one sponge layer inside the clean frame.
Chocolate Mousse
Heat yolk, sugar, and milk to 83°C. Pour over melted chocolate and emulsify. Fold in semi-whipped cream. Use part of it to cover the crunch layer.
Assembly
Place frozen insert (coconut side down) on mousse. Add second sponge layer. Fill to the top with remaining mousse. Smooth the top. Chill or freeze.
Temper chocolate. Spread over transfer sheet. Cut rectangles (3.5Ă—8 cm) before it fully sets. Cover and allow to crystallize fully (2+ hrs).
Final Touch
Remove cake from frame. Slice into 6 equal portions using a hot sharp knife. Pipe small dots of reserved mousse on top of each and place a chocolate plaque.
🎉 These slices are best served at room temperature when the mousse is soft and flavorful.