Lamingtons

Sponge cake

• 50 g unsalted butter, cut into pieces, plus extra to grease
• 120 g white sugar
• 4 eggs
• 1 tsp natural vanilla extract
• 120 g self-raising flour

Icing

• 30 g unsalted butter
• 160 g full cream milk
• 500 g icing sugar
• 50 g cocoa powder
• desiccated coconut or shredded coconut, to coat