• Preheat oven to 170C/340F. Prepare two 7" baking tins by greasing them and lining them with baking paper. In a separate bowl, combine self-raising flour, cocoa powder, and baking powder. Mix well and set the bowl aside for later.
• In another bowl, whip the butter for about a minute, add sugar and continue to beat the mixture using a stand or hand mixer for approximately 5 minutes, until it becomes light and fluffy.
• Next, crack an egg and add it to the butter and sugar mixture. Beat the mixture well to ensure the egg is fully incorporated. Repeat this step with the remaining eggs. After that, add half of the previously prepared flour mixture to the egg mixture and gently fold or whisk it in. Then, pour in half of the milk and stir it into the batter until it becomes smooth.
• Divide the batter evenly to the prepped tins and bake them in the preheated oven. Bake the cakes for 25-30 minutes. After the first 25 minutes, test the cakes by inserting a skewer into them. If the skewer comes out clean, the cakes are done.
• Finally, remove the cakes from the oven with care. Allow them to cool in the tins for about 5 minutes before transferring them to a cooling rack to cool down completely. Enjoy your homemade cakes!

White Chocolate Frosting

• Add unsalted butter to a large bowl.
• Whisk the butter on low speed for a few minutes until it becomes creamy and smooth.
• Then, add half of the icing sugar to the butter. Whisk on medium speed until combined.
• Next, add the remaining icing sugar, melted white chocolate and double cream. Whisk for 3-5 minutes or until the mixture is spreadable.

Decorate

• Start by spreading a tablespoon of white chocolate buttercream onto a cake board. Then place a layer of chocolate cake onto the prepared cake board.
• Next, spread a layer of white chocolate buttercream over the cake, ensuring it is smoothed out evenly. Then, sprinkle crushed Kinder Bueno over the buttercream layer and top it with another layer of chocolate cake. 
• Frost the whole cake with white chocolate buttercream and smooth out the tops and edges for a neat finish.
• Arrange milk and white chocolate Kinder Bueno pieces around it, then lightly dust the top of the cake with cocoa powder. For the final touch, pipe more white chocolate buttercream on top and garnish with chunks of Kinder Bueno.
• Serve and enjoy this luscious chocolate Kinder Bueno Cake!