I like to do these in a silicone brownie pan as well because the end result is just so pretty, but for expediency often do them in the Fat Daddio. The baking times are slightly less in the silicone (12-15 minutes) but the overall experience and mouthfeel is better. If you use the square pan, bake for 18-20 minutes and let them cool completely before eating. I often chill them in the fridge afterward for a fudgy treat. Left out they don't quite have the same chew as the cookies or the little mini squares.