Mix together the graham cracker crumbs, granulated sugar and melted butter. Pack into your pan. Chill while you make the filling.
Beat the cream cheese until smooth and creamy. Add in the chocolate/butter mixture and beat until combined. Beat in the powdered sugar, then fold in the whipped cream.
Layer the chocolate filling on top of the base and chill for three hours or overnight until set.
This is best served chilled. Store in the fridge.