I have a family size convection microwave oven instead of a full size oven. I make fruit cakes and have to change the tin for next year's competition. I've always used a round tin and now I have to use a square tin. How do I stop it from burning at the corners before the middle is cooked? I set it at 130 dgeress Centigrade and bake for 3-4 hours
First off, I personally love the hard edges of the brownie. But to your question: There are a few things that you can try to keep the edges from burning.
One last thing that might work that I have had to do with pie is wrapping foil around the edges until the last 10-15minutes of cooking.