Line a 9-inch springform pan with parchment paper and lightly grease the sides. Mix Oreo crumbs with melted butter until combined. Press firmly into the bottom and slightly up the sides of the pan. Chill while preparing the filling.

Beat cream cheese, sugar, and cocoa powder until smooth. Add melted chocolate and mix well. In a separate bowl, whip heavy cream, powdered sugar, and vanilla until stiff peaks form. Gently fold whipped cream into the chocolate mixture. Pour over the crust and spread evenly.

Refrigerate for at least 5–6 hours or overnight until fully set.

Whip heavy cream, powdered sugar, and vanilla until stiff peaks form. Remove cheesecake from pan, pipe whipped cream on top, and decorate with toppings.

Slice and serve chilled. Store leftovers in the refrigerator.