Are there cups that are wider than solo cups but shorter?

I use plastic cups for making molds in, and they're convenient because they have flat bottoms, are closed so they don't leak, and disposable so I can break them open to get the mold out. But I can only mold small things in them.

Is there a type of disposable wider than standard solo cups on the bottom, but not taller? I've tried using bowls and they're hard as hell to get the mold out, and anything without a closed bottom tends to leak.