I have to make a Death Star cake. My plan had been to do the bottom half in styrofoam to avoid having the cake collapse. I'm not great at sculpting and I have little confidence I can get the top half to match perfectly. As I'm looking around, I'm seeing a lot of people are doing both halves in cake. Do they hold up?? Are there tricks to this?

There's a tutorial on how to make a death star cake. On the front page, just "look at all tutorials", and you'll see it.

Thanks Mariann. I saw that actually. I know the author says he uses mud cake and ganache. My daughter really wants my chocolate chip cookie dough cake and buttercream filling. I'm just worried the weight would sink the bottom layer, you know?