Crush cookies into fine crumbs and mix with melted butter. Press firmly into a parchment-lined 8×8-inch pan. Chill while prepping the filling.
Beat cream cheese, powdered sugar, and vanilla until smooth. Mix in melted chocolate. Whip heavy cream to stiff peaks, then fold into the chocolate mixture in three parts. Spread over crust and chill for 2–3 hours.
Heat cream until it simmers, then pour over chocolate chips. Let sit, then whisk until smooth. Cool slightly, pour over cheesecake layer, and spread evenly.
Top with mini chocolate chips, curls, crushed Oreos, or whipped cream. Decorate as desired.
Refrigerate 2–3 more hours, or overnight, until firm. Slice and serve cold.