I decided to make my first chocolate sheet cake this morning. I'm a better cook than baker so when I managed to have nothing go awry by the time it went in the oven, I thought I was home free. But I was following those directions exactly and totally spaced that I had to compensate for using a 9x13 cake pan instead of a 15x10 jelly roll pan. So when that frosting went on top of seemingly ready cake, it fell straight through the middle. Horror! I whisked that cake/frosting disaster back in the oven and I left it there until I smelled crispiness. What I just took out of the oven looks terrible and I think it's straddling that border between over done and inedible. I'm willing to accept my failure and try again later today, nothing risked nothing gained and all, but I wanted to ask for some advice. What is the best way to adjust a recipe to compensate for using the incorrect sized pan? Should I be upping the temp and keeping the bake time or should I do the opposite? Buying more pans is going to be my permanent solution but I'm pregnant and if I don't get a good chocolate cake today I think someone is going to get cut.