1). Finely crush the Oreos with a food processor, blender, or in a Ziploc bag. Stir crumbs together with 8 tablespoons melted butter until well combined. Press into the bottom and sides of a pie pan. Freeze crust for 10 minutes until set.
2). While the crust is chilling, combine the three filling ingredients in a large mixing bowl or the bowl of a stand mixer. Beat on low speed until smooth and creamy. Spoon the peanut butter mixture over the crust into a smooth layer. Place back in freezer.
3). While that is chilling, combine the chocolate, cream and peanut butter. These three ingredients can be melted together in a microwave or in a bain-marie (double boiler) on a hob. The ganache is ready when the ingredients are blended smoothly. It will look glossy.
4). Pour the chocolate layer over the peanut butter layer so that the chocolate touches the edges of the Oreo crust. Refrigerate for at least 1 hour until ready to serve. Slice with a sharp knife and serve cold.