Simplify by baking the brownies in a 13x9-inch pan about 30 minutes or until toothpick inserted 2 inches from side of pan comes out almost clean. Cool at least 1 hour. After frosting, cut brownies into small squares (7 rows by 6 rows or smaller) and serve in miniature paper or foil baking cups.
Look for cans of chipotle chiles in adobo sauce in the international section of the grocery store.
If you don’t have enough mini muffin pans, refrigerate the batter until ready to bake and cool the pan 10 to 15 minutes before reusing; add 1 to 2 minutes to the bake time.