1) Unsalted Butter Softened
2) Salt
3) Confectioners’ Sugar
4) Vanilla Extract
5) Marshmallow Fluff
Beat together marshmallow fluff and butter in mixing bowl with electric mixer on medium speed until well combined.
Beat in milk a little at a time if needed, until frosting just comes together but only if needed.
Make sure your butter is completely softened so you don't get lumps in your frosting.
This frosting makes about 4 cups which should be enough for a thin layer on a cake.