Place the Oreo cookies in a food processor and blend at high speed until finely ground. With the processor running on low, slowly drizzle in the melted butter until the crumbs begin to clump together and pull away from the sides of the processor.

Press the crumb mixture firmly and evenly into the bottom and up the sides of a 9-inch pie plate. Place in the freezer to chill while preparing the next components.

Place chopped chocolate in a heat-proof bowl. Set aside.

In a small saucepan, combine the heavy cream and 1 tablespoon butter. Heat over medium-low until butter melts and small bubbles form around the edges—do not boil. Remove from heat and immediately pour over the chopped chocolate. Let stand for 2 minutes, then stir until smooth and glossy. Refrigerate for about 30 minutes to thicken slightly while making the filling.

In a large mixing bowl, beat together the cream cheese, peanut butter, and granulated sugar using an electric mixer on medium speed until smooth and creamy, about 2 minutes.

Gently fold in the thawed Cool Whip using a spatula until just combined. Do not overmix.

Remove the crust from the freezer. Spoon the peanut butter filling into the crust and smooth the top with a spatula. Return to the refrigerator for 30 minutes to firm up.

Pour the thickened but still pourable chocolate ganache over the chilled peanut butter filling. Use a spoon to spread evenly or create decorative swirls on top.

Refrigerate the pie for at least 2 hours, or until completely set. Serve cold.