Ok. So today I made a Mary Berry choc cake. There were 2 sandwich tins and I put them in the fan oven on the top shelf. They wouldn't fit equally next to each other so one was at the front and one more at the back. After 25 mins one was fine, but one had sunken a lot in the middle and looked uncooked (was also gooey to the touch). I left it it in for another 10 mins after checking it again after 5 mins and it cooked but was quite crumbly and a bit dry. How do you deal with 2 cake tins at the the same time and stop cakes being dry and crumbly? I would like it a bit mire dense. Thanks.