**I tried just about EVERYTHING to find the easiest way to get these brownies to come out cleanly. Muffin liners do not work, plain cooking spray and flour doesn't work.... The best solution was to rub shortening into each cavity and then lightly dust with cocoa powder (flour will work with the shortening, it just will make the brownies have a white-ish color). With shortening, these come out SO clean and easy. Do not skip this.