I am baking graduation cakes. Out of 6 cakes, 3 have completely sunken in the middle. What am I doing wrong. I am using BC. I am sifting. I am adding dry to liquid. I am baking larger pans on 300 then turning up to 325. I am not opening the oven while they are baking. Nobody is up but me, as it's the middle of the night and my kids are in bed.

adjust the baking powder (slightly less), a little less liquid, and scrap the bowl after creaming the butter and sugar, then again after adding all ingredients together.

You said you are using BC, meaning Betty Crocker? Is the cake mix still in date? Did you doctor it any? What size cake pans are you using? Are you using bake even strips or a heating core? How long are you baking them?

Is cake sinking before or after it comes out of the oven?

If it is sinking after it comes out of the oven a lot of the time that means it is under baked. Did you torte them to see if they were cooked completely through?

If it is sinking before it comes out of the oven, I'd think there is an issue with the cake mix, any subs you made or something else.

I use wasc and cut the sugar back to 3/4 c per box because mine always fell in the middle as well. Hasn't happened since and not as sticky!

Divinecc....I get so frustrated when I make WASC due to the tops being so sticky. The cake is always good and bakes nicely but they always get sticky before I am able to frost them. Thank you for the info, I will have to remember to cut the sugar next time.

I know I hate it, they still get a little sticky but not as bad!

I've had cakes sink in the middle after baking when I've over beaten the batter. As long as I stick to the recommended timing, I don't have an issue with it. Best of luck.

Maybe not done all the way? Or not beaten long enough.

I've had this happen once to me. I believe may have over beat the batter and I think it was the reason it fell in the middle. I don't usually have a problem with it falling in the middle. I most always use Duncan Hines as a starter mix and usually add ingredients. Duncan Hines is my tried and true!!
Good luck!!

How long is the batter "resting" or sitting out before you put it in the oven? Someone posted this article about leavening agents in a cupcake thread. I found it really helpful and learned that the chemical reactions for the leavening agents start as soon as you add the liquid, not once you put them in the oven (there is a secondary reaction that is heat based though). If you refrigerate the batter until your ready to put it in the oven it will help retard the reactions (not saying that it IS the problem, just a possibility)

http://www.seriouseats.com/2010/06/what-is-the-difference-between-baking-powder-and-baking-soda-in-pancakes.html

http://bakeryscience.com/caketechhelp.html

Use baking strips this helps the middle bake even with the sides of the cakes. I always bake my cakes at 325 degrees.

I've found that if you beat your batter too hard or for too long it will not bake properly. I usually beat on 4-5 on my kitchen aid, for 2-3 minutes.