Does anyone has an advice on this. I baked 2 14"x14" square cakes and they sank in the middle. It is the first time it happens this to my cakes. Any ideas of what i did wrong? Can i fix it by adding more cake in the middle to make it even instead of baking them again? I will stack a 10x10 and a 6x6 cakes on top. The cake is for a quinceañera, i am just affraid that if i stack it like that the whole cake will collapse.