As I was taking the cakes out of the pan (12"square) they fell apart. These cakes were for the bottom tier of a wedding cake I'm doing this weekend. Can i piece them back together, cover them in frosting and fondant and be good to go, or should I make them all over again. I'm worried the the dowels won't stay in place........I'm really stressing over this....

You might be okay. But why would you even consider taking a chance like this with somebody else's wedding cake, of all things? Re-bake.

If you are using a stacking system like SPS where the top tiers don't actually rest on the bottom tiers, you would probably be OK, but if you are only using dowels so the bottom tier has to support the top tiers, I would rebake.

Fell apart sounds worse than cracked in half. I'd rebake.

Even with SPS, a 'fell apart' cake could easily collapse on itself, even with no weight on it.

I wouldn't chance it. When you insert dowels, you are destabilizing the cake, to some degree. Inserting dowels into an already unstable cake is risky. I'd re-bake the cake.

Thanks everyone! I thought I'd have to rebake, but I wasn't sure.