I baked a wasc sheet cake and when it was cut it had a lot of holes in it. What did I do wrong?
Could have over mixed it. That will cause air bubbles. I try to let my pan sit for a few minutes to let air rise and then drop it on the counter a few times to bring them to the surface so I don't have holes in it like that.
Just like Patty mentioned. Try dropping it on the counter a few times to let the bubbles rise.