Preheat oven to 350°F and spray a mini-muffin pan with cooking spray. Prepare brownie batter as directed on package. Mix 1 cup of toffee bits into batter. Spoon brownie batter into muffin tin, filling about two-thirds full.
Bake for 10 to 15 minutes. Cool completely. Pour packet of Duncan Hines® Frosting Creations™ Caramel Flavor Mix into can of Duncan Hines® Frosting Creations™ Frosting Starter. Stir until evenly blended.
Frost brownie gems with a dollop of the Caramel frosting you just created. Sprinkle remaining ¼ cup toffee bits on top as a garnish.
Tip: For variety, try other mix-ins instead of toffee bits, such as mini-chocolate chips, nuts or chopped-up cookies.