nonstick cooking spray
2 cups creamy peanut butter
3/4 cup butter, softened
2 cups powdered sugar
4-6 cups pretzel twists
2 cups semi-sweet chocolate chips
Line a 13×9 pan with foil making sure to leave overhang at the ends. Lightly spray the foil with cooking spray. In a large mixer bowl, beat together 1 1/4 cups peanut butter and butter until creamy. Gradually beat in 1 cup powdered sugar. Stir in the remaining 1 cup powdered sugar, 3 cups pretzel pieces, and 1/2 cup chocolate chips. Press evenly into the prepared pan with a spatula.
Microwave remaining 1 1/2 cups chocolate chips and 3/4 cup peanut butter in a medium, microwave-safe bowl on MED-HIGH for 45 seconds; stir. If necessary, microwave in additional 10-15 second intervals, stirring just until chocolate chips are melted. Spread this chocolate layer evenly over the powdered sugar mixture in the pan.
Sprinkle with the remaining pretzel pieces, pressing down lightly. Refrigerate for at least 3 hours or until firm. Lift foil from the pan and peel off. Cut into 60 pieces and store in a covered container in the refrigerator. (Note: this get melty quickly, so I froze mine for an hour before placing out at party).