cake

I was thinking about doing a cake for my fiance during the rehearsal dinner. He's a HUGE Batman fan (HUGE is an understatement) and I would like something simple, with the bat symbol on it. His favorite thing in the world (after Batman of course) is cheesecake, but I don't know if that would work.

Can anyone give me an idea of how much this would cost? It wouldn't have to be a big cake - there should only be about 15 or so people at the rehearsal.

Thanks!