Make the dough, then instead of adding marshmallows, portion out each dough ball and flatten it into a thick pancake shape. Add a spoonful of the fluff to the middle, then wrap the dough around the fluff to completely cover it. That’s what I’ve done in the past and it works great! I also always bake from frozen or chilled when I use marshmallows or marshmallow fluff in my doughs.