Cream Nutella & cream cheese in a stand mixer with the paddle attachment until smooth. Scrape bowl. Add vanilla & mix again.
Fold in cool whip with a spatula until no white streaks appear. Spread into a prepared chocolate graham pie crust. Top with finely chopped chocolate. REFRIGERATE or FREEZE at least 2 hours to overnight.
Remove cheesecake from the fridge, slice & serve immediately. If removing from the freezer, allow the cheesecake to sit at room temperature for 5 minutes before slicing & serving.