Brownie Base
1 box (1 lb 2.4 oz) Betty Crocker™ Original Supreme Premium brownie mix
Water, vegetable oil and egg called for on brownie mix box
Filling
1/3 cup butter, softened
1/3 cup creamy peanut butter
1 1/3 cups powdered sugar
1 1/2 teaspoons milk
Topping
3/4 cup semisweet chocolate chips
3 tablespoons butter

Directions

1 Heat oven to 350°F (325°F for dark or nonstick pan). Grease bottom only of 8-inch or 9-inch square pan with cooking spray or shortening. (For easier cutting, line pan with foil, then grease foil on bottom only of pan.) Make brownies as directed on box. Cool completely, about one hour.
2 In medium bowl, beat filling ingredients with electric mixer on medium speed until smooth. Spread mixture evenly over brownie base.
3 In small microwavable bowl, microwave topping ingredients uncovered on High 30 to 60 sec; stir until smooth. Cool 10 min; spread over filling. Refrigerate about 30 minutes or until set. For brownies, cut into six rows by four rows. Store covered in refrigerator.