Last night, I tried my hand at covering a 6" cake in rolled fondant. When I was finished, it looked great. Everything was smooth and awesome.

I left it on the counter overnight.

When I woke up this morning, a rather large bubble had started to form on the top of the cake, under the fondant. It wasn't so bad at the time, but a few hours after I delivered it, my customer emailed me to say that the bubble had gotten bigger and had cracked the writing on top.

Any ideas on what caused the overnight bubble and how to fix it?

I can't say much (I've only made 1 fondant cake so far) but I've heard from other CC'ers and the instructor I had, that you can fix it by pricking it with a sewing needle. I don't know why it happens, though. I'm pretty sure i've read it here somewhere, I just can't remember. Sorry.

Wow! sorry to hear that happened to you. I've had bubbles before, but i've never had one to "grow" while on the cake. Really wierd. When first putting the fondant on the cake I gently smooth the top of the cake before smoothing the sides, as not to trap the bubbles in. Then there's always the case where one has gotten trapped, I just prick with a pin and smooth. Hope this helps a little.

If you can get a new syringe with a tiny needle..(i have one I just use for cakes), you can poke the needle in and remove the air then smooth the bubble out.

it can also happen if the cake isnt moist where the fondant is getting attatched.
xx