Bake the cake according to the instructions in a 9x13 size baking dish ( follow the back of the box for baking time)
While the cake is baking, in a food processor or blender, grind up about 14 or 15 Oreos until they are finely ground.
The last 1 minute of bake time, prepare the marshmallow creme by adding 2 cups of fluff in a microwave safe bowl and add 2 tbsp. of water. Microwave for 20 second intervals and mix in between each interval. Keep doing this until you get a looser consistency. Then, add about 1/2 of the finely ground Oreos into the fluff and fold it in. (about 1/2 cup of finely ground Oreos)
As soon as the cake comes out of the oven while it is warm, poke holes in the cake using the handle of a wooden spoon. Do NOT poke holes all the way through the cake. Poke the holes 3/4 of the way through the cake
Pour the marshmallow mixture all over the cake aiming for the holes so the marshmallow seeps in the holes.
Let the cake cool on the counter or in the refrigerator for about 1 hour before adding the whipped topping.
Whipped topping: In a bowl add 2 cups of heavy cream, 1/2 cup of powdered sugar, and a pinch of salt.. Blend with an electric mixer until stiff peaks are formed and it looks like whipped cream! Add a 1/2 cup of marshmallow fluff and blend again just until incorporated. (about 1 minute) Lastly, fold in the rest of the finely ground Oreos. fold in until incorporated.
Smooth the whipped topping over the cake.
Heat up hot fudge and swirl using a fork all over the cake.
Add crushed Oreos and sprinkle over the cake. Then add two whole Oreos right in the middle of the cake.
Serve it up and ENJOY!