My 4 year old granddaugher has make "cake in a cup" 4 times in the last three days while visiting me from out of state. Whether mommy and daddy want it or not, she's for sure going to make it.
I also bought the pre-made icing that comes in a sort of bag (Oreo flavor) so that she can squeeze some frosting on top. I only used the angel food and a German chocolate mix.