01 - Combine crushed chocolate cookies with melted butter in a bowl, mixing until evenly moistened. Press the mixture firmly and uniformly into the bottom of a 9-inch square or round springform pan. Transfer to the freezer for 15 minutes to firm up.
02 - Beat softened cream cheese, creamy peanut butter, and powdered sugar in a large bowl using an electric mixer until completely smooth and no lumps remain. Gently fold in the thawed whipped topping with a rubber spatula until uniformly incorporated. Spread the filling 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, then pour it evenly over the peanut butter layer, tilting the pan to spread.
04 - Cover the pan tightly and refrigerate for at least 4 hours, or ideally overnight, to allow all layers to set properly.
05 - Spread the remaining whipped topping over the chilled chocolate layer. Garnish with chopped roasted peanuts and chocolate shavings if desired. Slice into squares or wedges and serve well chilled.