Lamingtons are a sponge cake or butter cake cut into cubes, dipped in chocolate, and then dipped in desiccated coconut. Sounded good to me!
Bake the Lamington cupcakes a day before you want to serve them. The cake needs to sit out overnight to get a bit stale before it is frosted. Trust me - you'll like the stale cake. Frosting it on all sides moistens it up.