Hi, I wondered if anyone could help me please. I am having trouble with my brownies at the moment, they keep coming out of the oven with a thick crust on top and will crack badly when I cut into them. I have used the same recipe for a while now and have kept my ingredients the same, my method hasn't changed and I always bake them for the same amount of time and the same oven temperature. They always used to come out perfect everytime, but recently they haven't been. I'd be very grateful for some advice. Thank you!