There’s a good chance your oven’s temperature is very wrong — the temperature could be off by as much as 50 degrees.
One reason this could be is because the oven’s thermostat is usually in the back, though your food is cooking closer to the front. And, the way today’s ovens are made, a constant 350 degrees isn’t really possible. The oven will heat up past 350 degrees then stop. When the temperature drops below 350 degrees, it will start heating up again. So, in reality, if your oven is set to 350 degrees, it could really have a temp between 330 degrees and 370 degrees.
So, what can you do about this? Using your eyes and nose to figure out when your food is done may be the most viable option — or just buying an internal oven thermometer.
Oven temperature was actually a problem for our ancestors as well. Back in the day, some people would hold their arm over the oven. If they could hold it and count to 30 without scorching their arm, it wasn’t hot enough for bread. Bread bakers also used to dust flour on the bottom of the oven. If it turned black without catching fire, it was hot enough.