I start out with the basic ingredients for a cream cheese frosting and then just added Marshmallow Creme Fluff and flavoring. Just know, that I kind of do a look, feel, taste process when I make frosting - so it isn't always exact (shame on me) - but I will try my best to give you what I think is a close approximation of the measurements I used for the extra ingredients and I'm thinking it will be OH-KIZZAY!
Marshmallow Cream Cheese Frosting
2 Sticks Unsalted Butter at Room Temp.
1 8oz Package of Philadelphia Cream Cheese (that is my preference)
2 Cups Marshmallow Creme (Fluff is the brand name)
2-3 Drops Marshmallow Flavoring (optional)
1 tsp Vanilla Extract
4-5 Cups Confectioner's Sugar
On medium speed, blend together the butter, cream cheese and marshmallow creme until well combined and then add flavoring and the extract. On low speed, gradually add the confectioner's sugar*. Spread on cupcakes and enjoy!
*I like to create a cream cheese frosting that is firm enough to pipe but not too stiff. I also try not to make it too sweet and depending on the type of powdered sugar you use, it can get sweet. So, when adding in the sugar, do it gradually and go by taste and preference.