I'm making a Darth Vader cake for a friend, using an 11 x 15 for the body (torso), but am having an issue with the head. I have very, very bad carving / sculpting skills apparently, as I discovered this the hard way. So, I finally found a site that said she wrapped the inside of a toy darth vader mask with saran wrap and then pushed the cake into that, added filling, and layered it until it was "full". Then when you take it out, all the details of the face are perfect. But she said it needed to chill overnight...which is my problem. Since I hacked the first attempt tonight, I, of course, have to go to the store to get what I need to make another (I don't make cakes that often and only buy "what I need") but really don't want to get my kids out of bed to go right now, so I was hoping I could just bake the new one tomorrow...but then I will only have 1 overnight left... I am using ganache instead of BC for the first time under fondant, and after reading all the ganache threads, once I ganache the cakes, those need to sit overnight, as well, before adding the fondant. I just made my ganache and cakes, was going to ganache tomorrow and fondant Saturday morning. But, if I bake the head tomorrow, and then stuff it in the mask, will it "set" in time to be ganached tomorrow evening? So, I guess my question is this whole stuffing cake into the lined mask as a makeshift mold after it is already baked...and how to get it firm enough without an overnight...(I hope this makes sense) please help! And, thanks!

I think I'm missing something here. You still have the cake you tried to carve tonight, right? Use that. Mushed cake is mushed cake - you don't have to start with an uncarved one.

Well, I have some pieces but mostly crumbs from my sad carving attempt. Do I just mash them all in there and not worry about a filling?

You can mix a little frosting with it, like you do for cake balls. Not too much, or it gets a weird texture. Just enough to hold it together.