I'm using the White Velvet Butter Cake from The Cake Bible. I'm filling the jumbo silicone cupcake molds 2/3 full. The molds sit in a shallow cookie pan (for support). I'm baking in a Breville countertop convection oven. Because of the convection feature, the temp is turned down from 350 to 325 degrees.
While in the oven, they rise and seem to set at around 15 minutes, but at 20 minutes they start to crack. I pulled them out and they were still underdone in the middle, so I rotated the pan and put them back into the oven for another 7-10 minutes to finish. The cupcakes didn't start browning until the last few minutes so now they look overdone. Total baking time was probably 30 minutes.
I'm only having the problem with cupcakes, no issues with regular cake pans. Any ideas what am I doing wrong?
Thanks for any advice!