Upcoming in about a month or so my young nephew is having a birthday, and I'd like to bake him a cake. He'll be 4. Having observed his current eating preferences, I have some requirements.
First, it must either be able to be cut up into small, bite-size pieces (i.e. not slices but pieces - about the size of a pea) without affecting the ability to get the total experience of the cake in one such piece, or it must be able to be picked up with small hands and eaten as is, such that one entire dimension will fit into a small mouth (for example, a large roll doesn't work - you can't fit it in your mouth, but a large breadstick does
- it's easy to get the thin axis in your mouth and bite off a piece). A cake that you could slice into parts of this shape would also be fine, as long as the slice would not then crumble once picked up or bitten into, nor have to be held in a specific way (such as, for instance, carefully horizontal and icing-side up). The general concept is that it should not be in some way unwieldy to eat with hands.
Second, it shouldn't be excessively messy to eat. Believe it or not, this is a desire of the nephew as much as the parents - he hates getting messy or sticky.
Third, it should be powerfully chocolatey - of the same level of chocolatiness as desserts I typically make (see various recipes I've posted to get the idea). In other words, intense. And it mustn't be dry at that intensity level.
If it features blueberries, or goes great with blueberries on the side, that'd be a huge plus as well.
What suggestions do you have?