Ingredients

• 600g/1lb 5oz unsalted butter
• plus extra for greasing
• 600g/1lb 5oz caster sugar
• 12 free-range eggs
• 450g/1lb self-raising flour
• 150g/5½oz cocoa powder
• 150g/5½oz dark chocolate
• melted
• 300g/10½oz unsalted butter
• softened at room temperature
• 1 tsp vanilla extract
• 750g/1lb 10oz icing sugar
• 150g/5½oz white chocolate
• melted
• 300g/10½oz unsalted butter
• softened at room temperature
• 1 tsp vanilla extract
• 750g/1lb 10oz icing sugar
• 150g/5½oz dark chocolate
• melted
• 400ml/13fl oz double cream
• 400g/14oz white chocolate
• fresh flowers
• to decorate

Directions

• Preheat the oven to 170C/325F/Gas 3. Grease and line the 23cm/9in cake tin and 15cm/6in cake tin.
• Cream the butter and sugar together in a bowl until light and fluffy
• then beat in the eggs
• one at a time
• until well combined.
• Fold in the flour and cocoa powder
• then stir in the melted chocolate until well combined.
• Divide the mixture among the prepared cake tins.
• Bake the 23cm/9in cake for 1 hour-1 hour 15minutes and the 15cm/6in cake for 45 minutes or until the cakes are golden-brown and a skewer inserted into the centre of the cakes comes out clean.
• Remove the cakes from the oven and set aside to cool
• then carefully remove them from the tins and allow to cool completely.
• Meanwhile for the white chocolate buttercream
• cream the butter
• vanilla and icing sugar together in a bowl until light and fluffy. Stir in the melted chocolate.
• For the dark chocolate buttercream
• repeat the method for the white chocolate buttercream.
• For the ganache
• heat the double cream in a saucepan until just boiling
• then remove from the heat. Pour the cream over the chopped chocolate and stir until the chocolate has melted and the mixture is smooth. Set aside to cool slightly
• or until the mixture has thickened.
• Carefully cut each cake in half horizontally and fill with the dark chocolate buttercream. Spread a teaspoon of buttercream onto each cake board and place the cakes onto them.
• Spread the white chocolate buttercream over the top and sides of each cake until covered. Chill in the fridge for 30 minutes
• or until the icing has set.
• Spread the ganache over each cake with a palette knife
• trying to make it as smooth as possible. Chill in the fridge for 30 minutes
• or until the icing has set.
• To stack the cakes
• hold a dowelling rod at the side of the 23cm/9in cake and mark with a pencil where the icing comes to. Cut the rod and three others to the same length. Push the rods into the cake about 5cm/2in away from the sides
• to form the four corners of a square in the centre of the cake. Place the pillars on top of the largest cake
• positioning each one over a dowelling rod
• then top with the 15cm/6in cake. Decorate with fresh flowers.