Whip two containers of marshmallow creme in your mixer.
Adding one to two tablespoon at a time, gradually mix in 3 sticks (1-½ cups) softened, unsalted butter. Beat well.
Add ½ c. powdered sugar and beat in.
Add ½-1 teaspoon of strawberry extract (to taste) and a very small dot of pink gel food coloring.
Notes
Occasionally, people have trouble with the consistency of this recipe. I've made it probably a hundred times over the years and get consistently delicious and stable frosting. If your frosting is too soft - it is because your butter is too soft. Place the whole bowl in the refrigerator for 15 minutes, then try rewhipping.It is possible that the brand of butter and/or marshmallow creme could contribute to a different consistency. I typically use Costco butter (salted or unsalted) and Jet-Puff or store brand marshmallow fluff.This strawberry buttercream recipe is not shelf stable - it's primarily butter and will melt or become overly soft at room temperature or sitting out in the sun. Keep frosted goods in the refrigerator until serving.Use gel-based food coloring to deepen the pink color of the frosting. Liquid food coloring may change the consistency and flavor of the frosting. A dot of red food coloring will produce a pink frosting or you can use your favorite shade of pink.