So when I make my 8 inch cakes they come out perfect, but the last 3 times I've done a big 11x15 sheet cake the edges burn and so does the bottom. I had to cut the edges and cut the bottom off. I use the WASC recipe, and always cook it at 325, for 55min, just like I do for my 8 inch cakes, same time, same temp, but for some reason it burns. The pan I'm using is the Wilton gold. The batter amount was 12 cups in each one and I used 2 flower nails in the middle. The edges always shrink so much too.

Anyone know what I'm doing wrong?

I would try it at 300 degrees and moving the oven rack up one tier.

Forgot....at the first sign of edges pulling away from sides, the cake is generally
fully baked!

Oh seriously?! Because when I bake the 8 inch it also shrinks from the edges, so I should try taking them out earlier then, and I will try baking at 300 and moving the rack up. Never thought to move the rack up! Thank you!!

Yes, seriously!!! LOL I have never had an ''unbaked'' cake when I've removed it when they started to ''pull'' away from the pan. And I have
never had a ''burnt'' bottom!!! Good luck.......let us know how you make out doing this. It should work.

Hehe, thank you! I was starting to think that sheet cakes hated me. Ha!

Are you testing for doneness or just timing? Timing is just a guidline, when I start smelling cake and it's pulling away from the sides of the pan I start checking for doneness.

LOL No, no cakes hate you or anyone!!! Just keep an eye on them nearing the end
of baking time to see if they are starting to pull away and you'll be on your way to doing
yummy cakes.

Tiggy I do check with a toothpick, but I'm so paranoid with it not being done that I wait until there is absolutely NOTHING on the toothpick. Now I'm thinking a few crumbs on the toothpick is OK, just as long as it's not wet batter on the toothpick.

Thanks Cakes47!!

Yes, it is OK to have a few little crumbs. Definitely NO WET BATTER......besides, the sides wouldn't
pull away from the pan if it wasn't done. Now go bake and be happy!!!!

Haha! Yes Ma'am! I can't wait to bake it again now, and I will pull it out when I start to see the edges pulling in too.

Please let me know how you do with it. Good luck!!!

when I do a large sheet cake, I put 3 flower nails evenly spaced across the bottom to conduct heat into the center and wrap the pan in cake strips to slow down the outside edges. The cake gets evenly baked and no over browning on sides, bottom or top.

no crumbs on the toothpick is a sign the cake is overdone. I also bake at 275

Thank you! I tried to put my cake strips on it, but because the edges aren't straight I can't get them to stay on for the life of me.

a good way to keep the bottom from browning too much (if you're having trouble) is to stick the pan on a cookie sheet before baking, or once you think the bottom is probably brown enough.

Anytime I bake sheet cakes I line the bottom w/ parchment or wax paper (whatever I have on hand) and that also leaves the bottoms less browned.

As for checking for doneness definitely take it out when you get a few crumbs sticking to the toothpick, if it's totally clean it's overbaked! If you have wet batter on the toothpick, it's not done.

If you have a couple crumbs and the sides haven't begun to pull away, chances are it's not fully done either.

What do you mean, your edges aren't straight? Did you whack
the pan (from frustration) after your cake edges & bottoms came out burnt???

Hahaha, no that's why they are all dented!! No no, I mean the edges aren't at a 90 degrees, the very bottom is narrower than the top of the pan, so my beloved cake strips won't stay on, they slide right off before I even get the batter in. My 8 inch pans have straight edges, just not the sheet pan.

OH ... DUH I really couldn't picture your pans. LOL Sorry, now you can
go happily bake a cake.

Hahaha! You crack me up!

As long as the cakes don't crack!!

That's what I did to my last one, trying to "flip" it onto the second layer and cracked right down the middle. lol

OUCH!!! I generally slide cookie sheet under it and after putting the filling on the bottom layer,
slide, with the help of large spatulas the top layer on. Knock on wood it's worked so far.
I've seen where others have written in and said they use extra cake rounds or squares, etc to
do this. I hope I explained that OK.

Yes, couple of nights ago I posted on here because it cracked and I was freaking out. Thankfully someone suggested the same thing you did and so I got a cake board and it worked! lol Thankfully it didn't crack COMPLETELY in two, but almost. Learning as I go!

The more I learn, the more I find to learn. Never ending process. Glad you could
save your cake!! Have to get a few things done, as much as I would rather
be on here it's not to be. Enjoy the rest of your day and happy baking!!!!
Joyce

Thanks Joyce for your help! Have a great day!

I bake at 365, but I also use the flower nails for larger cakes.

If I'm worried a cake might get a bit overdone on the sides or bottom, I satnd it on a thick piece of cardboard in the oven...works really well especially for heavier cake mixtures