01 - Combine the crushed chocolate sandwich cookies and melted butter in a medium mixing bowl until the crumbs are evenly moistened. Press the mixture firmly into the bottom of a 9×9-inch baking dish to form an even, compact layer. Place the dish in the refrigerator to chill while preparing the next layer.
02 - In a large bowl, beat the softened cream cheese, creamy peanut butter, and powdered sugar together using an electric hand mixer until completely smooth and lump-free. Gently fold in 1 cup of thawed whipped topping with a rubber spatula until evenly incorporated. Spread the peanut butter mixture in a smooth, even layer over the chilled cookie crust.
03 - In a separate bowl, whisk the instant chocolate pudding mix with the cold milk for approximately 2 minutes until the mixture thickens and becomes glossy. Pour the pudding over the peanut butter layer and spread it out evenly using a spatula.
04 - Spread the remaining 1 cup of whipped topping over the chocolate pudding layer in smooth, even strokes. If desired, drizzle with the melted peanut butter and sprinkle with chocolate shavings or mini chocolate chips for garnish.
05 - Cover the baking dish tightly with plastic wrap and refrigerate for at least 3 hours, or until all layers are fully set and firm to the touch.
06 - Using a sharp knife, cut the chilled dessert into even squares. Serve chilled directly from the refrigerator.