Okay, so does anyone have experience baking in a pan this size? I had a cake catastrophe tonight and am loosing my mind

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First my mixer burnt up, so I had to run and get another one. I got that one home and it plain didn't work. I took that one back to the store and got a new one, and finally resumed baking at about 8:30pm. After all that with the pan delay (previous posts) and now the mixer, the cake burnt on the top, bottom and sides but was perfectly done in the middle. In other words, garbage
Was my oven too hot? Or did I need a heating core? Any advice would be great as I have to try this again tomorrow.
I am super sad that I lost another day on this one

It has to be done by Saturday morning... I'm at my wits end here.