This is the case when you marry yogurt and marshmallow fluff. Marshmallow fluff is like a melted marshmallow -- light and airy with a vanilla sweetness that makes you feel like a kid when you it ...
Add the marshmallow creme and beat until combined. Scrape the filling into a resealable plastic bag and snip a corner. Pipe a large dollop of filling onto the flat side of half of the cookies.