Am on the scrounge for tasty but healthy cake recipes to put in ds's lunchbox

[Overrun]

I have a great one for carrot cake, but any other ideas would be gratefully recieved.
I am in a bit of a baking mood and figure it will be a way to give him a treat without having to resort to a biscuit or worse

I was under the impression carrot cake was one of the most unhealthy out there, in terms of calories! What is your recipe?.....and flapjacks are healthy if you make them yourself x