In a large bowl, add the pudding mix, cream cheese, sugar, vanilla, and milk. Using a hand beater, beat until everything comes together and becomes creamy and smooth. Add the frozen whipped topping into the mixture and fold until fully incorporated.
Add the majority of the Oreos to the mixture and fold them in using a rubber spatula. Add the marshmallows and fold again until mixed together. Cover and refrigerate for a minimum of 30 minutes
Add the fluff mixture to a serving bowl and top with the leftover Oreos and marshmallows. Serve and enjoy!
Notes
Letting the fluff mixture chill in the fridge for at least 30 minutes allows the flavors to meld together and firms up the texture for a better consistency when serving.
Store in an airtight container in the fridge for 3-4 days.
You can use regular-sized Oreos; simply crush them up.