Demetrius, thanks for your critique. I think these are all really great ideas, especially the uplighting and some kind of reflection on the glass. The cakes were a bit opaque, except for the chocolate one, which must be a kind of sacher. But that's not to say I can't change them.
Mostly, I was trying to decide about a style issue. I wanted a look almost like cut paper or printmaking, with as much rich, flat color as the situation would allow, and I was going for high contrast to draw attention to the boy, and mostly just the one cake. But now that I've finished this version, I can try others as well. In fact, I was already thinking of doing so. So I'll probably give this a try!