Ok, I'm about to make this cake for the THIRD time!! I'm getting extremely irritated at this point. The first time I used the Fat Daddio pan (10x15x3) and it was a disaster... half the cake overcooked and other half never cooked! (I also used a heating core) I"m about to throw that pan in the garbage!

So... then I figured I would use my 11x15x2 Wilton half sheet cake pan. Well, the cake cooked just fine, but after letting it cool about 20 minutes (which is part of my routine), half of it got stuck to the pan! What the heck is going on?? I use the Wilton cake pan spray with the flour to coat the pan (which always works fine in my other pans).

I'm wondering since I have to use 3 boxes of mix that if each time i add the batter to the pan it displaces the grease/flour mixture?? What the heck else could it be? Not letting it cool off enough? Should I use something else to keep the cake from sticking? I need your help please!! Like I said, this will be the THIRD time I"m making this dang cake and I don't want to waste anymore time or money. Thanks!!

Instead of pouring the batter in separately, try mixing them all together in a large bowl and pouring it in all at once. I also use flower nails instead of a heating core. HTH

I line the bottom of ALL of my pans with wax paper. I use homeade pan grease (equal amounts of oil, shortening and flour blended together). I "paint" the pan grease on the inside of my pans using a pastry brush then I cut a piece of wax paper to go in the bottom of the pan and grease that as well. I NEVER have a cake to stick when lining with wax paper. Like I said you have to grease your pan as well but I never bake any cake w/o lining my pans. Also, I only cool in the pan for 10 minutes not 20 minutes.

And Ditto to what nannycakes said

Since I started lining my pans with parchment paper I never have trouble with sticking. I grease sides and bottom of the pan (or at least about 2 inches around the edge of the bottom) and lay paper smoothly in bottom of pan; proceed as normal. I don't use any flour, I take the cake out of the pan at 10 minutes, and remove the paper as soon as I take the cake out of the pan.

I have never had good luck with the Wilton cake pan spray. The cake release works so much better! I always remove my cakes after 10 minutes of cooling.

When I first started I was mixing each cake mix separately then I found on the pillsbury website (the mixes I use) that you can mix two mixes at the same time, but it does say no more than two. This definitely helps get at least one "layer" on the bottom of your pan.

I spray my pans first (have even used Pam) and then I line my pans with parchment paper and spray it. Pour all the batter in at one time and I use the flower nails instead of a core. When your cake comes out of the oven cool it for 10 minutes in the pan and then put the cooling rack over the top of the cake pan and flip. This supports all of the cake and allows the whole cake to come out at at once. I then remove the parchment paper and allow to cool. I've never had a cake stick!
evelyn

Thanks ladies!!! I have taken all of your suggestions and have put them to use. The cake is the oven! Thanks so much! I'm really embarrassed that I never thought to put wax paper on the bottom before... that makes total sense! Lesson learned. Thanks again!

I use home made pan grease, no parchment paper and take my cake out of the pan anywhere from the time it comes out of the oven to about 10 mins afterward. My cake hardly sits in the pan for longer than 10 mins, the longest would be 15..

It's nothing like having something like this happen to you to make you question your insanity and your baking ability!! I know I've had stuff like this happen out of the blue and it's frustrating! I have been brushing the Wilton Cake Release into my pans for several years. I use a silicone brush so there is easy cleanup. When I take the cakes out of the oven, I try not to let them set for any longer than 10 mins before removing them from the pans. I've read on here a few years ago that if they start to stick as you remove them, pop them in the heated oven again for a few minutes. I have tried it only once or twice and have had that work. HTH! Good luck!