Home ovens tend to heat hotter from either the top or the bottom. Good news: It’s not just because your oven is Older, even the new ones heat unevenly. You’ll know if the bottom is hotter, for instance, if you’ve noticed cookies getting dark on the bottom, while the top stays pale (or vice versa). To fix this, try putting an empty baking sheet on the shelf either above or below the item you’re baking—whichever is hotter. This will absorb some of the heat and help things bake or roast more evenly.
“gas oven not cooking evenly. I have an old Hardwick gas oven. i can’t seem to bake anything evenly despite having had the temperature tested by the gas company and told that it was accurate. … If the outside is overcooked and the inside is undercooked, your oven is running hot.May 2, 2009