@RenegadeMonster he will literally put the entire tray back in the oven on broil from 15 minutes so that the whole thing is charred like the outer pieces, because that's how he rolls.
When my mother makes brownies, she always use a pampered chef pan that makes mini loves that are bite size. So every browner has all 4 corners and all 4 edges and is also considered the middle piece. They are already, but I do think brownies taste better when cooked as one large single unit. I love when they are moist, chewing and make you want to guzzle milk. My mothers brownies are often dry.