If you mix up the batter in the amounts that the recipe calls for, and then bake in a larger pan, the cake will not fill the pan when it rises. The extra metal at the top that is ultimately not filled with cake does present a problem to the finished product. I’m sorry to say that I don’t remember what the problem is, but Hector would probably know. I think the info is in the blog some where. Do a search for 3 ” pans and see what you come up with.