Whisk together vanilla pudding mix and milk until smooth and there are no lumps. Cover and let the pudding thicken in the fridge.
In a medium sized bowl, beat cream cheese on medium speed with an electric mixer until smooth and creamy. Add powdered sugar and mix until incorporated.
Next, add the vanilla pudding and mix well. Divide the mixture in half, into two bowls. In one bowl, mix in 1/2 cup Nutella. In the other bowl, add the marshmallow fluff and mix well. Fold 1 1/2 cups Cool Whip into each bowl.
Fill the graham cracker crust half way with the Nutella mixture. Then top with the marshmallow mixture. (It may be helpful to let the Nutella layer freeze a little bit before trying to spread the marshmallow layer on top.)
Melt the remaining 1/4 cup Nutella in the microwave and drizzle on top of the pie. Use a toothpick to swirl the Nutella into the marshmallow layer.
Freeze overnight for best results! Thaw 10-15 minutes before serving.