I just took some out of the oven and there’s always that tissue-paper layer on top that settles down again as they cool. What makes that happen?
Mmmmmmmmmmm, brownies. . . .</drool>
I’ve wondered about that myself. Since brownies use baking powder and soda to rise rather than yeast it can’t be the heat clobbering the leavening action and making a crust that way.
I imagine it has something to do with water soluble stuff like sugars and starches hitching a ride in the steam of the cooking batter, and then getting deposited on the surface when the steam hits the hot air and dissapates. Might explain the ‘crackle’ as well – sugar and starch are more brittle than the ‘cakey’ part and might contract different as the surface cools (i’m thinking like the carmelized lid of a creme brulee).
Don’t hold me to any of that though…
Those ugly berets.
It’s caused by the lack of a rich chocolate frosting.
Peace,
mangeorge