Preheat oven to 160C (325F). Place the butter and sugar in an electric mixer and beat for 8-10 minutes or until pale and creamy. Gradually add the vanilla and eggs, beating well after each addition. Add the flour, baking powder and coconut and mix to combine. Add the buttermilk and mix to combine. Spoon into a lightly greased 20 cm x 30 cm tin lined with non-stick baking paper and smooth the surface with a palette knife. Bake for 35-40 minutes or until cooked when tested with a skewer. Cool in the tin for 10 minutes before turning out onto a wire rack to cool completely.

To make the icing, place the icing sugar, cocoa, water and butter in a bowl and whisk to combine. Cut the cake into 3 cm squares, toss in the chocolate mixture to coat and roll in the coconut. Allow to set before serving. Makes 60.