Chocolate Cake

1. Preheat the oven to 330°F (165°C) and line two 6-inch (15 cm) round cake pans with parchment paper.
2. In the bowl of a stand mixer fitted with the whisk, whip the eggs, sugar, and vanilla on medium-high speed for 10 minutes, until pale, fluffy, and tripled in volume.
3. Meanwhile, sift together the cake flour, cocoa powder, baking powder, baking soda, and salt.
4. Reduce the mixer speed to low and gently mix in the dry ingredients, just until combined.
5. In a separate bowl, whip the cold heavy cream to stiff peaks.
6. Mix a small amount into the batter to loosen it, then gently fold in the remaining whipped cream with a spatula.
7. Divide the batter evenly between the pans and bake for about 1 hour, until a toothpick inserted in the center comes out clean.
8. Let cool slightly, unmold, then cool completely upside down on a wire rack. Wrap and refrigerate for at least 2 hours before assembling.

Kinder Chocolate Ganache

1. Place the chopped chocolate and Kinder Maxi pieces in a heatproof bowl.
2. Heat the heavy cream until just simmering, then pour over the chocolate. Let sit 1 minute, then stir until smooth. Blend if needed.
3. Cover with plastic wrap touching the surface and chill overnight.
4. The next day, whip the cold ganache for 3–5 minutes, add the mascarpone, and whip again until light and creamy. Keep refrigerated.

White Chocolate Swiss Meringue Buttercream

1. In a heatproof bowl, combine egg whites and sugar. Heat over a double boiler, whisking constantly, until the mixture reaches 160°F (71°C) and the sugar is fully dissolved.
2. Transfer to a stand mixer and whip on high speed until the meringue is stiff and completely cool.
3. Gradually add the softened butter, mixing until smooth and creamy.
4. Mix in the melted white chocolate, vanilla, and salt. Keep at room temperature until ready to use.

Chocolate Drip

1. Heat the chocolate and heavy cream together until smooth and fluid.
2. Let cool slightly and use at 85–95°F (30–35°C) for dripping.

Assembly & Decoration

1. Slice each cake into 4 even layers.
2. Place the first layer on a cake board, pipe a buttercream border, fill with Kinder ganache, and add chopped Kinder Bueno. Repeat with all layers.
3. Cover the cake with white chocolate buttercream and smooth the sides.
4. Add the chocolate drip, then decorate with buttercream swirls and Kinder Bueno pieces.
5. Chill for at least 2 hours, then remove from the fridge 30 minutes before serving.