Nonstick cooking spray
2 cups creamy peanut butter, divided
3/4 cup (1 1/2 sticks) butter, softened
2 cups powdered sugar, divided
4 cups (roughly 1/2-inch pieces), broken small gluten-free pretzel twists, divided
2 cups (12-ounce package) Nestlé® Toll House® Semi-Sweet Chocolate Morsels, divided
Line 13 x 9-inch baking pan with foil, leaving an overhang on two sides. Lightly spray foil with nonstick cooking spray.
Beat 1 1/4 cups peanut butter and butter in large mixer bowl until creamy. Gradually beat in one cup powdered sugar. Stir in remaining 1 cup powdered sugar, 3 cups pretzel pieces and 1/2 cup morsels. Press evenly into prepared baking pan. Smooth top with spatula.
Microwave remaining 1 1/2 cups morsels and 3/4 cup peanut butter in medium, uncovered, microwave-safe bowl on medium-high (70%) power for 45 seconds; STIR. If necessary, microwave at additional 10- to 15-second intervals, stirring just until morsels are melted. Spread chocolate layer evenly over powdered sugar mixture. Sprinkle with the remaining pretzel pieces, pressing down lightly. Refrigerate for at least 3 hours or until firm. Lift from pan; peel off foil. Cut into 60 pieces. Store in covered container in the refrigerator.