2
Mix together graham cracker crumbs, confectioners' sugar, butter or margarine, and 1 cup peanut butter in a medium bowl until well-blended.
3
Press evenly into the bottom of an ungreased 9x13-inch pan.
4
Place chocolate chips and 4 tablespoons peanut butter in a microwave-safe bowl.
5
Microwave on high, stirring every 15 seconds, until smooth.
6
Spread mixture over crust.
7
Refrigerate for at least 1 hour before cutting into 12 squares.