Any tips on making a belly cake that will feed more people? I am thinking to stack rounds and carve but I'm a little nervous about how to get a smooth look after carving.

Set the belly cake ontop of a slab cake for more servings.

I did just what Kiddiekakes suggested a couple of months ago. It looked great and made plenty enough to go around (I'd love to show you, but I haven't had a chance to post it yet - sorry!).

How many can the "regular" belly cake serve. I'm making one for a shower this weekend and they are expecting 30 guests. Would that be enough, or do I need to make a sheet cake to go underneath?

My belly cake feeds about 10 people I say. I use the half ball pan and 2 mini wondermolds. If I need more servings I put it on a sheet cake. I did one a month or so ago that sat nicely on a 10" square.