In a bowl, mix chocolate cookie crumbs and melted butter. Press into a 9-inch springform pan and chill.
In a large bowl, beat cream cheese until smooth. Add powdered sugar and vanilla, and mix until well combined.
Pour in melted chocolate and mix until fully incorporated.
In a separate bowl, whip the heavy cream until stiff peaks form.
Gently fold whipped cream into the chocolate mixture.
Spread the filling over the crust, smoothing the top.
Refrigerate for at least 4 hours or until set. Serve chilled.