Update: my oven runs 25 degrees hot and I only found out from a $9 thermometer
I grabbed an oven thermometer at a hardware store in Boise three weeks back and it showed 375 when I had the dial set to 350, which explains why my chocolate chip cookies kept coming out flat and crispy instead of chewy, so now I want to know if anyone else has caught their oven lying to them like this or if mine is just extra sneaky.
Did you check it at more than one temp? I ask because my last apartment had an oven that was fine at 350 but went totally rogue up at 425, like 40 degrees over. I figured that out the hard way with a frozen pizza that came out looking like a charcoal frisbee. Now I test any oven at two or three settings before I trust it with cookies.