290g packet white
chocolate melts gel food colouring in red,
blue, yellow and green 2 x 600g store-bought white chocolate mud cakes BUTTERCREAM 125g unsalted butter,
softened 1½ cups icing sugar, sifted 1 tablespoon milk
1. In a bowl over a saucepan of simmering water, melt chocolate. Divide between 4 bowls.
2. Using a little colouring, tint chocolate red, blue, yellow and green. Working quickly, dollop 2 teaspoons of one colour onto a baking paper-lined tray. Using a pastry brush, brush the chocolate up slightly to form a brushstroke.
3. Repeat, washing and drying the pastry brush between colours. Set aside at room temperature to firm.
4. BUTTERCREAM. Use an electric mixer to beat butter as white as possible. Gradually beat in icing sugar and milk.
5. Remove icing from store-bought cakes and level with a large serrated knife. Sandwich together with a little buttercream on a cake board. Spread top and sides of stacked cakes with buttercream.
6. Arrange brushstrokes on the front of cake and press gently into icing to stick.