I am making a Mickey Mouse cake. 8 Round for the head and 4 rounds for the ears. I have the cakes frosted and ready for fondant. My question is how to add a chin to the 8 round after Ive already frosted it. Ive noticed Mickeys face isnt totally round, he has cheeks and a chin, so I want to be able to add to the shape of the cake. Can I mold a block of fondant and place it against the cake? How would I secure it? Toothpicks and frost over it? Or maybe I could make cake ball dough and use that. I have some cake scraps I could use. I have already frosted it, but I can always scrape some of it off. Thanks for any advice.

You can use fondant, cake scraps, rice krispie treats - pretty much anything edible. You could use toothpicks or skewers to secure them, but I recomment piping gel. If you do use toothpicks, be sure they're removed before the cake is served.

I think fondant or cake ball mush would work just fine without toothpicks. The icing should be sufficient glue.

Or, you can use spackle, which is like cake ball mush but with more icing. It will naturally stick to the icing. The only thing is, you'll have to partially freeze the cake before applying the fondant, otherwise, it will squish around.