Heat oven to 350 degrees F. Coat one Brownie Bite pan or two 12-cup mini muffin pans with nonstick cooking spray.
Microwave butter and chocolate together for 1 minute. Stir until smooth. Mix in flour, sugar and salt. Whisk in eggs and vanilla until smooth. Transfer batter to a plastic bag. Snip off a corner and squeeze batter into indentations. Bake at 350° for 12 minutes. Cool in pan(s) on wire rack.
Once cooled, remove brownies to a platter. Transfer frosting to a plastic bag and snip off a corner. Pipe onto brownies, then top with toasted coconut, chopped mints, chopped pretzels or chopped pecans. Drizzle hot fudge over the mints and pretzels and caramel over the pecans.