Place Oreo cookies in a food processor and pulse until small crumbs. Stir in the melted butter.
Press the mixture into a deep dish 9-inch pie plate, covering the bottom and up the sides of the dish.
Refrigerate while you make the cheesecake filling.
For the cheesecake:
Preheat the oven to 325°F.
Add softened cream cheese to a large bowl beat with your stand mixer or electric mixers until fluffy.
Add eggs, 1 at a time, beating after each addition. Add vanilla and sugar and mix well, scraping down the sides of the bowl.
Fold in the Oreo chunks. Pour batter into Oreo pie shell and bake for 35-45 minutes or until the edges are set and the center is slightly firm (it can be a little soft, just not jiggly).
Remove from oven and cool completely.
For the Ganache:
Once the pie is cool, make the ganache. Combine the butter and cream in a saucepan over medium heat until the butter is melted and the mixture is simmering.
Place the chocolate in a small bowl. Pour the hot cream mixture over the chocolate and stir until melted and smooth.
Add the vanilla and powdered sugar and stir well. Pour the ganache over the cheesecake, carefully smoothing to cover the top evenly.
Refrigerate until ready to serve (at least an hour - the pie can be made up to a day in advance).
To make-ahead: Not only can this cheesecake be made ahead of time, but I recommend it. Make it one day in advance and store it in the refrigerator until serving.To freeze: You can freeze this cheesecake for up to 2-3 months. Cover it well before freezing. To thaw, place it in the refrigerator overnight.