1. Mix the chocolate cookie crumbs and melted butter in a bowl until the mixture looks like damp sand. Press it firmly into the bottom and sides of a 9 inch pie dish, then chill for 20 minutes.

2. Melt the semi-sweet chocolate until smooth using a microwave in short bursts or a double boiler. Let it cool slightly.

3. Beat the softened cream cheese in a large bowl until smooth. Add the powdered sugar, cocoa powder, and vanilla extract, then mix until creamy.

4. Blend the melted chocolate into the cream cheese mixture until fully combined and silky.

5. In a separate bowl, whip the heavy cream to soft peaks if using fresh cream. Fold the whipped cream or whipped topping gently into the chocolate mixture.

6. Spoon the filling into the chilled crust and smooth the top evenly.

7. Refrigerate the pie for at least 4 hours, or until firm and sliceable.

8. Finish with chocolate shavings or curls before serving.