Prevent Hard Brownie Edges
When making brownies, you can prevent the edges from getting hard. First of all, use an oven thermometer to make sure your oven temperature is accurate. Then test for doneness toward the end of the baking time. If the brownie springs back when lightly touched in the center and the sides have started to pull away from the pan, it is done.
If your brownie recipe has a cake texture (rather than a dense fudgy consistency), it’s done when a toothpick inserted in the center comes out clean. Avoid dark-colored baking pans, which can cause the edges to brown too fast. Finally, try lowering your baking temperature by 25°.