Peanut Butter Brownies

1   box fudge brownie mix ,Water, vegetable oil and eggs called for on brownie mix box                                           

                                                                    

3/4 cup creamy peanut butter                                           
1/4 cup butter
2  cups powdered sugar                     
2  teaspoons milk
                                         

1  cup semisweet chocolate chips       

1/4  cup butter                                             

• Heat oven to 350°F. Grease a 13x9-inch pan with cooking spray.  Make brownies as directed on box. Cool completely.
•  In a bowl, beat filling ingredients with electric mixer on medium speed until smooth. Spread mixture evenly over brownie base.
• In small microwavable bowl, microwave topping ingredients uncovered on High 30 to 60 seconds; stir until smooth. Cool 10 minutes; spread over filling. Refrigerate about 30 minutes or until set.   Store covered in refrigerator