In a large mixing bowl beat the cream cheese and powdered sugar until combined. Add the Nutella and milk and beat for 5 minutes, until thoroughly combined and somewhat fluffy. Fold in the cool whip.
Spoon into completely cooled hazelnut crust and refrigerate for at least 4 hours to allow pie to set.
Notes
Note – Due to the richness of both the crust and the filling, this pie is best served in smaller slices.