Okay - - I've been asked to make a 12" round Hummingbird cake. My recipe makes a 3 layer, 9" round cake. I've never made a Hummingbird cake before, not that it matters much. I'm trying to figure out how much additional cake batter to make to fill 3 - 12" pans, versus 3 - 9" pans. Anyone done this before? The ingredients in this cake are more expensive - beyond the normal flour/sugar, etc, there's crushed pineapples, bananas and pecans. I really don't want to have to over-buy to make sure I have enough as I will probably never make this cake again unless this customer reorders.

Thanks!

a 12 inch round requires about 7 1/2 cups of batter it also really depends on your cake batter and how much it rises. Do you tort your layers? If not you will need about 22 cups of batter which should make three cakes. If you do tort them you will need about 15 cups which will make two cakes and you can tort them to have four layers. I fill my pans 2/3 full.

Three 9x2" cakes are 382 cubic inches. Three 12x2" cakes are 679 cubic inches. 679 divided by 382 = 1.77. You need to multiply your recipe by 1.77 (or maybe just 2 if that's easier)

Awesome! Thank you so much y'all!!! I appreciate the help so much!!