For the longest time, my husband and I have known that our over temperature did not match what the dial said. We tried to adjust the temperature to a lower number and even shortened the baking time, but things still came out over-done or even burnt. We bake our pizza on the oven rack and when he checked the last pizza we baked, it was just starting to burn on the edges, but wasn't even hot in the middle.
Last night was the final straw. I baked a persimmon pudding and the recipe called for one hour at 350° f. I set my timer for 50 minutes and the oven dial at 325°. After 50 minutes, I checked it and found it done in the middle so I removed it to cool. But, before turning the oven off, I checked the bottom of the pudding and found the edges burnt black. My husband said he had found an in-oven thermometer the other day and went to get it. Leaving the oven at 350°, we put the thermometer inside for about 15 minutes. What we found was that our over temperature was 75 degrees higher that what the dial was set at. No wonder everything was burning. While I'd love to have a new stove, knowing the temperature difference will save us the money of purchasing one. Now, I will just adjust the temperature. I made biscuits this morning and they came out perfect. No burnt bottoms.
If your oven is doing the same thing, I highly recommend purchasing a thermometer for your oven. I did a google.com search this morning and found several web sites where you can buy one. Or, if you prefer to shop local as I do, visit your local hardware store and see what they have to offer. Holiday baking is going to be so much better this year.