Preheat oven to 425 degrees Fahrenheit (220 degrees Celsius).

Place the marshmallows on a lined, sprayed baking sheet. Place in oven and bake for four to five minutes. Remove and let cool.

Meanwhile, defrost the ice cream for about half an hour. Place into a mixing bowl and add the marshmallows. Mix well and return to the original container or a pan to freeze. Freeze until serving.

Lower oven heat to 350 degrees Fahrenheit (175 degrees Celsius).

Combine sugar, oil, and water in a saucepan set over medium heat. Heat until it starts to boil and remove from the heat. Add the chocolate chips and vanilla. Stir until completely smooth. Mix in the eggs one at a time, whisking vigorously. Add the remaining ingredients and mix until smooth.

Line a round springform pan with Gefen Parchment Paper. Crush two to three graham crackers and mix with melted margarine. Press into the bottom of the pan. Pour in half the brownie batter. Add chestnut-sized pieces of cookie dough and large blobs of marshmallow fluff.

Crush the remaining graham crackers loosely between your fingers and sprinkle on top. Add the remaining half of the batter and some more cookie dough balls, blobs of marshmallow fluff, and more crushed graham crackers.

Place in oven and bake for 45 minutes.

Let cool. Cut into slices, top with a scoop of ice cream, and serve.