In a medium bowl, combine chocolate cookie crumbs and melted butter. Press firmly into the bottom and up the sides of a 9-inch pie dish. Refrigerate while preparing filling.
In a large bowl, beat cream cheese until smooth. Add peanut butter, powdered sugar, and vanilla; beat until well combined.
In a separate bowl, whip 1 1/2 cups heavy cream to stiff peaks. Gently fold whipped cream into peanut butter mixture until no streaks remain.
Spoon filling into crust and smooth the top. Refrigerate for at least 4 hours, or until set.
For the ganache, place chocolate chips in a small bowl. Heat 1/4 cup heavy cream until just simmering, then pour over chocolate. Let stand 1 minute, then stir until smooth. Let cool slightly.
Pour ganache over chilled pie and spread evenly. Refrigerate for another 30 minutes until ganache is set. Slice and serve.
Tips
For a firmer pie, freeze for 1 hour before serving.
Store leftovers in the refrigerator for up to 5 days.
Garnish with chopped peanuts or chocolate shavings if desired.