I need a recipe for a 11 x 15 x 3" sheet pan perferably vanilla but I'll take anything but chocolate and I'm not using cake mix. I made a mango cake lastnight and 1 it did not cook in the middle and 2 it tasted horrible! And I need this cake for today.. Help!!!

Sorry I can't help w/a recipe as I bake mainly from mixes. I still suggest my *original* WASC http://cakecentral.com/recipe/the-original-wasc-cake-recipe the fact that the cake didn't cook in the middle is probably due to the fact it's a 3" deep pan & you didn't keep it in the oven long enough Deep pans require more baking time.
Use a flower nail in the center if you are having that problem often.

Why don't you bake this in three layers each 1" deep. MUCH easier to handle.