Brownies are the dense, rich offspring of the marriage of a cookie and a cake. While they need a pan that will help them keep their shape, the pan doesn't have to be as deep as a traditional cake pan. The type of pan you use can mean the difference between a tall, moist, cake-like brownie or a thin, chewy one.
Most traditional recipes and packaged brownie mixes call for an 8-inch by 8-inch square baking pan. However, some recipes -- often called "family size recipes" -- yield more brownies and require a 13-inch by 9-inch rectangular pan. Use a smaller pan for higher, more cake-like brownies and a larger pan for thinner, chewier brownies.
The Little Pan That Can
Bake brownies in either glass or metal, non-stick pans. Because metal pans hold heat longer, baked goods such as brownies don't need to cook as long. Baking brownies in a glass pan results in products with a chewier edge and more moist center.