This Is Why Your Oven Isn't Baking Evenly
Find those hot spots!
Every home cook and baker out there needs to spend a little time getting to know how his or her oven heats up. Every oven is different and will give you different results (read this to know how gas and electric ovens can affect your baking), and these two tips for figuring them out are incredibly easy!
The first tip comes from The Kitchn's article on renowned baker Dorie Greenspan: use shredded coconut to figure out your oven's hot spots: place a baking sheet filled with evenly spread-out shredded coconut inside your oven set at 350°F. Every once in a while, check the color of the shredded coconut. If you see parts of the tray where the coconut browns faster than other spots, this is where your oven heats up the most.
Another way of figuring out how your oven heats up is with white sliced bread. It's the same concept: spread them out on a tray and watch which slices go brown faster than the others. This way, you'll know exactly what to expect when you roast a chicken or bake a batch of chocolate chip cookies.
If your oven does have hot spots, make a conscious effort to turn your baking sheets around every now and then. It'll also help to purchase an oven thermometer to help you get an accurate reading on your oven's temperature.