I tried this recipe for the first time last weekend in an attempt to find a buttercream that I like nearly as much as my favorite Swiss Meringue Buttercream, but that I can whip up in a hurry. I found that if I beat it for a couple of extra minutes at the end, it got even more smooth and fluffy. It was delicious, and very quick and easy to make.
Classic Vanilla Buttercream Frosting
1 lb. unsalted butter (4 sticks), softened, but not melted. (Left at room temperature for several hours or overnight is best.)
6-8 cups confectioner's (powdered) sugar, sifted
pinch of table salt
2 tablespoons pure vanilla extract (or use clear vanilla extract if you need bright white frosting)
2-4 tablespoons milk or heavy cream (or more if needed)
Beat butter for a few minutes on medium speed in a mixer fitted with the paddle attachment. Add 6 cups of powdered sugar and turn mixer to lowest speed until the sugar has been incorporated with the butter (to avoid sugar from flying everywhere). Increase mixer speed to medium and add vanilla extract, salt, and 2 tablespoons of milk/cream and beat for 3-5 minutes. If frosting needs a more stiff consistency, add remaining powdered sugar. If you would like it thinned out, add remaining milk 1 tablespoon at a time.