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Kristen is the Creative Director of Food52
Yes, Fluff is a particular brand of marshmallow creme, so they're pretty much interchangeable in baking (even though aficionados claim Fluff is a must for fluffernutter sandwiches!).
You've got your answer but be aware that fluff/creme contains eggs where marshmallow does not and that is important to people with allergies (I bake for one.)