In a food processor, process the Oreos until they are crumbs and pour those crumbs into a medium sized bowl.
Melt the butter and mix with Oreo crumbs and sugar. Stir until a sticky dough is formed and then press the Oreo dough into the bottom of a springform pan. Press the crumbs throughout the bottom of the pan and a little up the sides.
In the same bowl (less dishes!) you used to make the crust, put in the cream cheese. Using hand mixers, mix the cream cheese for about 30 seconds to 1 minute. Slowly add in the sweetened condensed milk and continue to mix with the hand mixers for about 3-4 minutes.
Using a spatula scrape down the sides and continue to mix for another minute. Turn off the mixers and pour in one packet of hot chocolate. Stir the hot chocolate until incorporated and then add in the next packet. Repeat this step until all six hot chocolate packets are incorporated in the mixture.
With the spatula, fold in the cool whip until it is completely incorporated. Be careful to not over-mix the cool whip with the rest of the ingredients.
Then mix in the marshmallow fluff so it swirls around with the rest of the ingredients. Barely mix in the fluff so there are marshmallow ribbons throughout the pie.
Pour the mixture into the pan on top of the Oreo crust.
Freeze overnight or for at least 8 hours. Thaw for about 10 minutes before serving and return any leftovers to the freezer after served.