I am a big fan of the WASC recipe. I use it all the time. I am now baking my second batch/attempt at WASC chocolate cupcakes and find that again they are sinking at about the 17-minute mark after rising for a short period. I do not have this problem with the WASC recipe using white cake. I have increased the oven temp slightly and still had the same problem on the second batch. I reduced mixing time on the second attempt too. Still the same. I had lengthened the baking time on the first batch and found them too dry/overbaked.
Any similar experiences with the chocolate?
P.S. I use egg whites, not whole eggs.
My guess is the all whites recipe is what the problem is.
Yolks give the batter structure.
I guess I just assumed that because the egg whites worked well with the white cake mix, they would work just as well with the chocolate cake mix. Wrong assumption? (stumped)
Actually, all whites are better than whole eggs in the chocolate WASC for cupcakes. It took a few experiments, but I finally figured out it was the yolks that were making my chocolate WASC recipe cupcakes spongy and gross. I just baked a batch of choc WASC cupcakes with whites only and they are PERFECT!
A few other things you can check for -
Is your cake mix past the expiration date?
Fill the cups with a little less batter. Try just 2 or 3 at a time while you're figuring out the right amount.
Are you using the new smaller box of cake mix? I think it's Betty Crocker that has decreased the amount of mix in the box. If the other ingredients aren't adjusted, that could cause problems.