01 - Combine crushed chocolate sandwich cookies with melted butter in a mixing bowl, stirring until the crumbs are evenly coated. Press the mixture firmly into the bottom of a 9-inch square or round springform pan, creating an even, compact layer. Transfer to the freezer for 15 minutes to firm up.
02 - In a large bowl, beat softened cream cheese, creamy peanut butter, and powdered sugar using an electric mixer until completely smooth and free of lumps. Gently fold in the thawed whipped topping with a rubber spatula until uniformly combined. Spread the peanut butter mixture evenly over the chilled cookie base.
03 - Place semisweet chocolate chips and heavy cream in a microwave-safe bowl. Heat in 20-second intervals, stirring between each burst, until the mixture is glossy and smooth. Let the ganache cool slightly for 2 to 3 minutes, then pour it evenly over the peanut butter layer, tilting the pan gently to spread.
04 - Cover the pan tightly with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to allow all layers to set completely.
05 - Spread the remaining whipped topping evenly over the set chocolate layer. Garnish with chopped roasted peanuts and chocolate shavings if desired. Slice into squares or wedges and serve well chilled.