I have a small side business making brownies. I make them with different toppings. I make them in a 15" x 35" baking pan that just fits in my home oven. The sides are close to the oven.
I cook the brownies at 350 degrees. When I cook th brownies plain- with no topping, they come out in 25 minutes. With toppings (chocolate chips, walnuts, white chocolate pieces) the brownies take longer to set up. If I cook the brownies without a cover the white chocolate browns and does not make for a good presentation. Most of the browning occurs around the outside of the pan.
I've tried using aluminum foil and also covering the pan with another sheet pan. The trouble with covering the pan directly is that the brownies don't cook in the middle of the pan and the outsides are overcooked. I've also tried placing a cover on the rack above.
Please give me any tips to keep the white chocolate from browning.