Step 1

To make buttercream, using an electric mixer, beat butter in a large bowl until pale. Gradually sift in half the icing sugar, beating until pale and creamy. Beat in milk. Gradually sift in remaining icing sugar, beating until well combined.

Step 2

Remove icing from white chocolate mud cakes; discard icing. Using a large serrated knife, level tops of cakes to sit flat.

Step 3

Stack the cakes on a cake board, spreading between each with some of the buttercream. Reserve ¼ cup of buttercream; spread top and side of cake with remaining buttercream. Chill cake for 1 hour.

Step 4

To make ganache, combine white chocolate and cream in a heatproof bowl. Microwave on High (100%) in 30-second bursts, stirring between each, until smooth. Tint ganache with a little pink food colouring. Spoon ganache around edge at top of cake, allowing it to drizzle partway down the side. Chill for 10 minutes or until ganache is firm.

Step 5

Tint the reserved buttercream with a little pink food colouring; dollop over top of cake. Decorate with strawberries, raspberries and rose petals.