Took me 3 weeks to learn my oven runs 25 degrees cold, and I burned $60 of butter testing it
Bought a $9 oven thermometer from Ace on 5th, and my cookies finally stopped spreading flat after I bumped every recipe up 25 degrees, so am I the last baker on earth to figure this out the hard way?
Oh man, my friend Dana went through almost the same thing last winter. She kept blaming her flour and her butter temp and even bought a new baking sheet, then finally grabbed a $7 thermometer and found out her oven was running 30 degrees hot on top of it all. Turns out the thing had been slowly drifting for years and she never noticed because she mostly used it for frozen pizza. She felt so dumb but honestly the oven was the dumb one. You are for sure not the last person, this happens to everybody at some point.