Instructions

• Line a 9×13-inch pan with parchment paper, leaving about a 1-inch overhang on two opposite sides; very lightly spray the parchment with pan spray and set the pan aside.
• Place 30 Oreos (not double stuffed) in a food processor and pulse until finely ground.
• Add 6 tablespoons salted butter (room temperature) to the Oreo crumbs and pulse until the butter is fully incorporated and the mixture holds together when pressed.
• Transfer the Oreo mixture to the prepared pan and press into an even layer using your fingers or the bottom of a flat measuring cup. Chill the crust in the freezer for 20 minutes.
• While the crust chills, melt 1 cup salted butter (use microwave or stovetop) and let it cool slightly if very hot.
• In a large bowl, combine the melted 1 cup salted butter, 2 cups graham cracker crumbs, 2 cups powdered sugar, and 1 cup of the 1¼ cups creamy peanut butter. Stir until the mixture is smooth and evenly combined.
• Remove the pan from the freezer and spread the peanut-butter filling evenly over the chilled Oreo crust. Smooth the top with a spatula.
• Reserve the remaining ¼ cup creamy peanut butter. In a heatproof bowl, combine that reserved ¼ cup peanut butter with 1½ cups semi-sweet or milk chocolate chips. Melt together until smooth—either in the microwave (stirring every 30 seconds) or over a double boiler—stirring frequently to prevent burning.
• Pour the melted chocolate–peanut butter mixture over the peanut-butter layer and spread evenly with a spatula.
• Refrigerate the assembled bars for at least 1 hour to set. Use the parchment overhang to lift the slab from the pan and cut into bars. Store leftovers in the refrigerator.