Bake a batch of lamingtons with the Attendant, London
Mix all of the ingredients for the sponge in a bowl with an electric whisk. Grease a rectangular cake tin. Spoon the mixture into the tin and bake for 50 mins at 170C.
For the icing, add all the ingredients in a glass bowl, and melt over boiling water on a saucepan. Then add the water and whisk in by hand.
Cut the sponge into equal squares (6.5cm x 6.5cm) and cover all over with the chocolate icing allow to cool for a few minutes and sprinkle or roll with coconut.