Preheat oven to 350 degree F. Lightly coat twelve 1-3/4-inch muffin cups with cooking spray; set aside. In a medium saucepan melt butter and chocolate over low heat. Remove from heat. Cool 3 minutes. Stir in sugar. Add egg and vanilla, beating lightly with a wooden spoon just until combined. (Don't overbeat.) Stir in flour and the 1/4 cup peanuts.

Divide batter evenly among prepared muffin cups, filling each nearly full. Bake about 15 minutes or until set (wooden toothpick will not come out clean, nor will brownies spring back). Cool brownies about 3 minutes in pan; remove to a wire rack to cool.

Meanwhile, in a heavy small saucepan stir ice cream topping and peanut butter over medium-low heat until smooth. Remove saucepan from heat.

Divide ice cream into 6 serving containers. Top each serving with 2 brownies, and, if desired, banana slices. Drizzle with chocolate-peanut-butter sauce. Top with chopped peanut butter cups and additional peanuts, if desired. Makes 6 servings.

Prepare and bake brownies. Store cooled brownies tightly covered up to 1 day.