Make the crust. Add all of the Oreos to a food processor and process for 30-60 seconds, or until the cookies turn into crumbs. Add the melted butter to the cookie crumbs and pulse to combine.Alternatively, seal the cookies inside of a gallon-sized zip top food storage bag. Roll a rolling pin over the bag to crush the cookies into crumbs. Then transfer the crumbs to a bowl and stir in the melted butter well to combine.
Press the crust mixture into a greased pie plate. Transfer the crust to the refrigerator or freezer for 30 minutes.
Make the filling. In the bowl of a stand mixer (or use an electric hand mixer and mixing bowl), mix together the Nutella and cream cheese until smooth and slightly fluffy. Fold in the Cool Whip with a spatula until combined.
Scoop the Nutella filling into the chilled crust, then use an offset spatula or the back of a spoon to smooth out the top.
Return pie to the fridge for 1 hour to allow the filling to set.
If desired, garnish the top with whipped cream and cookie crumbs before serving.
Notes
For a thicker crust, use 3 cups of cookie crumbs and 7 tablespoons of melted butter.
Feel free to substitute graham crackers or a different flavor of Oreos for the crust.
Be sure to thaw the Cool Whip before using.
For a nicer presentation, you can garnish the top of the pie with whipped topping and/or cookie crumbs before serving. For a little extra nuttiness, you can also sprinkle it with chopped hazelnuts.
Store leftover pie in the fridge for 3-4 days, covered. Or, freeze for up to 1 week. It does not become completely frozen in a regular freezer, so you do not need to thaw very long (if at all) before serving.