The phrase "marshmallow fluff" refers to a soft and gooey spread made with marshmallows. It is sweet and often used as a topping for desserts like ice cream or as a filling for sandwiches and cookies. Full definition
I had just finished baking the peanut butter crunch brownies when I spotted the big tub of marshmallow fluff in my baking cabinet and got inspired. (lemonandmocha.com)
Set aside 3/4 cup marshmallow fluff in a small bowl; reserve remaining fluff for another use. (bonappetit.com)
Before I saw this though, i would say it's homemade devil dogs with homemade marshmallow fluff filling. (kitchenkonfidence.com)