1-Preheat oven: Preheat oven to 170°C (340°F) and grease and line two 7-inch baking tins with parchment paper.

2-In a bowl: sift together the self-raising flour, cocoa powder, and baking powder.

3-In a separate bowl: beat the unsalted butter for about 1 minute, then add the sifted caster sugar and whisk for 5 minutes until fluffy.

4-Add the eggs: one at a time, mixing well after each addition to blend smoothly.

5-Gently fold in: half of the flour mixture, add half the milk, and mix to a smooth batter; repeat with the remaining flour and milk.

6-Divide the batter: evenly between the prepared tins.

7-Bake: for 25-30 minutes, or until a skewer inserted into the center comes out clean.

8-Let the cakes cool: in the tins for 5 minutes, then transfer to a wire rack to cool completely.

9-Prepare the frosting: by whisking butter until creamy, adding icing sugar in two parts, then mixing in melted white chocolate and double cream until smooth and spreadable.

10-Assemble the cake: Spread a thin layer of white chocolate buttercream on a cake board, place one cake layer on top, add a generous layer of buttercream and sprinkle with crushed chocolate bars, then add the second layer.

11-Coat the entire cake: with remaining buttercream, smooth it out, decorate the sides with whole chocolate bar pieces, dust the top with cocoa powder, and pipe swirls of buttercream with chocolate chunks on top.

12-Serve and enjoy: your freshly made Kinder Bueno Cake.