When baking brownies, it is generally recommended to bake them on the middle rack of your oven. Placing the brownie pan on the middle rack helps ensure even heat distribution, which promotes even baking and helps prevent over-browning or undercooking.
Baking brownies on the top rack may cause the tops to brown too quickly while the center remains undercooked. On the other hand, baking them on the bottom rack may result in excessive browning on the bottom before the center is fully cooked.
By placing the brownie pan on the middle rack, you allow for more balanced heat circulation, helping the brownies bake evenly throughout and achieve a desirable texture and doneness. However, oven temperatures can vary, so it's always a good idea to follow the specific instructions in your brownie recipe and adjust accordingly based on your oven's behavior.