Preheat oven to 375
Add cake mix, eggs, oil, vanilla and sprinkles to a large bowl and stir until fully incorporated.
Using a small cookie scoop, scoop even balls of the cookie dough onto a parchment lined baking sheet.
Leave 2 inches between each ball of dough so it has room to expand
Bake in a 375 degree oven for 10-12 mins or until the edges begin to brown.
All to cool.
Make the marshmallow icing by beating fluff and butter until smooth.
Add in the confectioners sugar a little at time beating until smooth.
Icing should not be super stiff but fall into a ribbon pattern.
Using the same scooper from the cookies, add one scoop of icing to the cooled cookies.
Roll in the sprinkles.
Serve at room temperature or serve cold.