Name: Rosie HILLSBOROUGH, NC (Zone 7b) If it sparkles - I'm there!
Don't have a commercial oven but I have found lower rack does not have to be moved to middle...I just bake for shorter time...and at about 10-15 degrees cooler....if not it is a whole cake overcooking issue not just the top browning.
But it sounds like you have it all figured out anyway...that surely is an oven that you have to get to know....unless a repair person can get it calculated to accuracy
Don't squat with yer spurs on!
People try to turn back their "odometers." Not me. I want people to know 'why' I look this way. I've traveled a long way and some of the roads weren't paved
