01 - Preheat the oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine the crushed chocolate sandwich cookies with melted butter until the mixture resembles wet sand. Press firmly and evenly into the base of the prepared pan. Bake for 10 minutes, then set aside to cool slightly.
03 - Using an electric mixer, beat the softened cream cheese and granulated sugar together until completely smooth and free of lumps. Add the creamy peanut butter and sour cream, blending until fully incorporated.
04 - Add the eggs one at a time, mixing on low speed just until each is incorporated. Stir in the vanilla extract. Avoid overmixing to prevent excess air in the batter.
05 - Pour half of the filling over the cooled crust. Drizzle half of the melted dark chocolate over the batter and gently swirl with a butter knife. Add the remaining batter and repeat with the remaining melted chocolate, creating decorative swirls throughout.
06 - Bake for 50 to 55 minutes, until the edges are set but the center still has a slight jiggle. Turn off the oven, crack the door open, and allow the cheesecake to cool gradually inside for 1 hour.
07 - Remove the cheesecake from the oven and transfer to the refrigerator. Chill for at least 4 hours or preferably overnight to allow full setting.
08 - Heat the heavy cream in a small saucepan until hot but not boiling. Pour over the finely chopped dark chocolate and let stand for 2 minutes. Stir until glossy and smooth, then blend in the peanut butter.
09 - Spread the ganache evenly over the chilled cheesecake. Allow the topping to set for at least 30 minutes before slicing and serving.