Heat 1 3/4 cups chocolate chips, 1 cup marshmallows and milk in a medium saucepan over low heat stirring until marshmallows are melted(do not overheat) Pour into large bowl and cool to room temperature.
Whip the whipping cream in a small bowl until stiff peaks form. Fold 3 cups of the whipped cream and remaining marshmallows into chocolate mixture. Spoon into crust and swirl the top of the pie.
Garnish with remaining whipped cream and remaining chocolate chips.