About this recipe:This is my mum's chocolate sandwich cake recipe which she used to make for all the birthdays in our house. Now I make it for my family! The secret is to add whisked egg whites so the chocolate sponge cake is light. The chocolate buttercream filling and icing for this cake is easy to make and hides a multitude if your chocolate sponge cake doesn't turn out perfectly!
Preheat the oven to 180 C / Gas 4. Lightly grease 2 (20cm) sandwich cake tins.
Use an electric mixer or beaters to cream the175g butter and sugar together until the mixture is smooth. Add the egg yolks and continue to beat until light and fluffy, about 5 minutes.
Stir the 100g cooled, melted chocolate into the milk and mix well. Add to egg mixture, then gradually mix in flour and baking powder; beat for another minute until mixture is an even colour.
In a separate bowl, whisk egg whites until stiff. Gently fold the egg whites into the chocolate cake mixture until evenly mixed. Divide the mixture between the 2 cake tins.
Bake for 30 minutes or until a skewer inserted into the centre comes out clean. Cool on a wire rack.
To make the buttercream filling: blend the 60g softened butter and icing sugar in a food processor or beat together with an electric beater. Add the 60g cooled, melted chocolate and vanilla and stir together until evenly mixed.
When the cake has cooled, use a long serrated knife to slice throught the middle of each cake, creating 4 layers.
Spread the chocolate buttercream over each layer and then over the top. Decorate with whatever cake decorations you like.