9x9 or 9x13?
I have a cake recipe that calls for a 9x9 pan. If I double the recipe can I use a 9x13? I know the square inches are different, but thought I'd ask anyway
An 8 x 8 square pan is 64 square inches, and I've often doubled recipes by using a 9 x 13, which is 117 square inches. Usually the baking time is only marginally longer.
To double a 9 x 9 pan and bake in a 9 x 13, would yield a taller end result of the cake, and no doubt need a longer baking time. Depending on the type of cake you are baking, you could get into a little bit of trouble with an overflow of batter during the bake cycle.
You might try increasing the recipe by 50%. The cake will be a bit higher and, I suppose, need a bit more baking time. Unless your 9 by 13 pan is really deep, however, I think that doubling the recipe would give you a good excuse to clean your oven.