A "true" Fluffanutter sandwich is made like this:
Take two slices of white Wonder bread. On one slice, spread a nice layer of Skippy peanut butter. On the other slice, spread a similar thickness layer of Fluff marshmallow cream.
Place the two together, peanut butter touching marshmallow cream, then cut in half.
Now you have a real Fluffanutter. And yes, you need to buy and use these brand names, although if all you can find is Bond bread in your area, it will do.