Using a medium sized mixing bowl and a handheld electric mixer on medium-high speed, beat the cream cheese for 1 to 1½ minutes, until smooth.
Sprinkle in the pudding mix and continue mixing for another 30 seconds to 1 minute, until well combined.
Add the marshmallow fluff and continue mixing just until incorporated.
Fold in the thawed Cool Whip.
Evenly spread the Cool Whip mixture into the premade crust, and chill in the refrigerator for 8 hours. Just before slicing, add the ½ cup thawed Cool Whip to the center of the pie. Slice and serve immediately.
Notes
This recipe needs to chill in the fridge for about 8 hours before it is ready to serve. This is a great recipe to make the day before so that it is ready when you need it.
Make sure your cream cheese is at room temperature so that you don't have lumps in your creamy filling.
If your pie crust is in a foil tin, we'd recommend sitting it inside a glass pie plate to give it a bit more stability.