• Lightly spray a 9-inch round springform pan with non-stick cooking spray.

Oreo Crust

• Pulse the Oreo cookies (wafers and filling) in a food processor until fine crumbs. Or place in a freezer bag and crush with a rolling pin.
• Mix in the melted butter - either stir together with a fork in a small bowl, or add the melted butter to the food processor and pulse a few times until combined.
• Press the mixture into the bottom and up the sides (about 1/2 to 3/4 to the top) of the springform pan.
• Place in the freezer as you make the filling.

Cheesecake Filling

• In a large bowl, beat the whipping cream until stiff peaks form. Set aside.
• In a separate large bowl, beat together the cream cheese and sifted powdered sugar until smooth and creamy (about 3-4 minutes). Occasionally turn off the mixer and scrape down the sides and bottom of the bowl.
• Beat the peanut butter, sour cream and vanilla into the cream cheese mixture. It will be very thick. Again, be sure to occasionally turn off the mixer and scrape down the bottom and sides of the bowl.
• Carefully fold the whipped cream into the peanut butter mixture using a rubber spatula. Gently fold the mixture until you no longer see and streaks of whipping cream. The mixture should be an even consistency when finished.
• Spoon the mixture over the crust and smooth the top.
• Cover the pan and place the cheesecake in the fridge to set for at least 6 hours or overnight. I typically make the cheesecake the night before I plan to serve it.

Chocolate Ganache

• Finely chop the chocolate and place in a heatproof bowl.
• Heat the cream until almost boiling - this can be done either in 30 second intervals in the microwave (go slowly to avoid burning) or in a double boiler.
• Pour the hot cream over the chopped chocolate and let sit for 2-3 minutes. Then whisk until smooth. If the chocolate hasn't quite melted, microwave for 30 seconds on medium power (not high or the chocolate can burn or bake) and whisk. Repeat as needed. Alternatively, place the bowl over a double boiler over gently simmering water and whisk until smooth.
• Remove the cake from the fridge. Trace around the outside of the cake with a sharp knife, then unclamp the springform pan.
• Pour the ganache over the cheesecake and smooth into an even layer. Place back in the fridge until ready to serve.

Serving

• Optionally, beat the additional 1/2 cup whipping cream until stiff peaks form. Transfer to a piping bag with a star tip (I used a 1M tip). Pipe rosettes of cream around the edges of the cheesecake and decorate with peanut butter cups.
• Slice into pieces using a thin, sharp knife, being sure to cut through the crust. For clean cuts, wipe the knife in between each cut.