Lamington

Name: Lamington
Prep time: 25 min
Cook time: 30 min
Total time: 55 min
Cuisine: Australian
Ingredients: 125g (1 cup + 1 tbsp) butter, softened; 200g (1 cup) caster sugar; 1/2 tsp vanilla extract; 3 eggs; 220g (1 ¾ cups) self-raising flour, sifted; 120 ml (1/2 cup) milk; 180g (2 cups) desiccated coconut; ICING; 300g (2 ½ cups) confectioners' sugar; 30g (1/4 cup) cocoa powder; 1 tbsp butter, softened; 120 ml (1/2 cup) boiling water