Six-layer cake

White chocolate ganache

• 330 g pouring (whipping) cream
• 900 g white chocolate broken into pieces

Cakes

• 300 g unsalted butter cut into pieces and softened, plus extra for greasing
• 1020 g plain flour
• 810 g white sugar
• 3 tbsp baking powder
• 3 pinch salt
• 750 g full cream milk
• 3 tsp natural vanilla extract
• 6 eggs

Buttercream icing

• 500 g icing sugar (see Tips)
• 240 g unsalted butter cut into pieces and softened
• 1 tbsp boiling water
• 1 tsp natural vanilla extract