Prepare the crust by mixing the melted butter with the Oreo cookies crumbs in a medium bowl until you've reached the texture of wet sand.

Grease and line a 9-inch pie pan with 2 layers of cling wrap. Pour the cookie mixture into a lined pie pan and press the cookies into the pan using your fingertips. Place in the fridge to set for roughly 20 minutes while you make the filling.

Add chocolate and cream into a bowl and heat in the microwave or over a bain marie for about 2 minutes, until the chocolate is melted. Stir in vanilla extract and set aside and allow to cool to room temperature.

Once cooled, Using an electric mixer, beat the chocolate mixture on High speed until it starts to thicken, about 3-4 minutes.  

Spoon filling into the prepared pie crust and level with a spatula. Refrigerate for at least 4 hours or until set. 

When ready to serve, pile the whipped cream high in the center of the pie and grate over some chocolate to garnish. Keep refrigerated for 3 days.