01 - Preheat oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine crushed chocolate sandwich cookies with melted butter until evenly moistened. Press mixture firmly into the bottom of the prepared pan. Bake for 10 minutes, then set aside to cool slightly.
03 - Beat softened cream cheese and granulated sugar with an electric mixer until completely smooth. Add peanut butter and sour cream, blending until uniformly combined.
04 - Add eggs one at a time, mixing on low speed until just incorporated after each addition. Stir in vanilla extract. Avoid overmixing to prevent cracks.
05 - Pour half of the filling over the baked crust. Drizzle half of the melted dark chocolate over the batter and swirl gently with a knife. Add the remaining batter and repeat with the remaining melted chocolate.
06 - Bake for 50 to 55 minutes, until the edges are firmly set but the center still has a slight jiggle. Turn off the oven, crack the door open, and let the cheesecake cool inside for 1 hour.
07 - Remove from the oven and refrigerate for at least 4 hours or overnight for best results.
08 - Heat heavy cream in a small saucepan until hot but not boiling. Pour over chopped dark chocolate and let stand for 2 minutes. Stir until smooth and glossy, then mix in peanut butter until fully blended.
09 - Spread ganache evenly over the chilled cheesecake. Allow to set for at least 30 minutes before slicing and serving.