In a mixing bowl, combine the chocolate cookie crumbs and melted butter until evenly coated. Press the mixture into the bottom of a 9-inch springform pan to form the crust. Bake for 10 minutes, then let it cool.
In a large mixing bowl, beat the softened cream cheese until smooth. Gradually add the peanut butter and continue to mix until fully blended.
Add the powdered sugar and vanilla extract to the cream cheese mixture. Beat until fluffy and well incorporated.
In a separate bowl, whip the heavy cream to stiff peaks. Gently fold the whipped cream into the peanut butter mixture until no white streaks remain.
Pour half of the cheesecake filling over the cooled crust and spread evenly. Drizzle half of the melted chocolate over this layer and swirl with a knife for a marbled effect.
Add the remaining cheesecake filling on top, smoothing out the surface. Drizzle the remaining chocolate on top and swirl again.
Refrigerate the cheesecake for at least 4 hours, or overnight, until fully set.
Once set, carefully remove the sides of the springform pan.
Before serving, sprinkle crushed peanuts and chocolate shavings on top for added texture and garnish.