Combine the graham cracker crumbs and sugar and mix together. Add the melted butter and mix until the crumbs are moistened.
Press the crumbs into a 9-inch pie pan. Chill in the refrigerator while the filling is being made.
Prepare the chocolate by grating or processing it in a food processor until finely chopped.
In a double boiler add the marshmallows and milk. Over medium-low heat melt the marshmallow, stirring constantly.
Once the marshmallows are melted remove from the heat and stir in the vanilla.
Add the chopped chocolate and stir until the chocolate is melted and mixed in.
Let the chocolate mixture cool to room temperature.
Whip the whipping cream until stiff peaks. Fold the whipping cream into the cooled chocolate mixture until well combined.
Pour the filling into the prepared pie crust. Refrigerate.