1 cup (2 sticks) butter (salted, or unsalted)
1/4 teaspoon salt (if using unsalted butter)
4 cups powdered sugar
1 teaspoon vanilla extract (best quality available)
*Optional- As mentioned above, I like a cream cheese version of this frosting best. The cream cheese adds to the creamy texture, and cuts down on the sweetness just a bit. If desired, for a very light cream cheese flavor add 1/2 block (4 oz). cream cheese, leaving the other ingredients (as listed above) the same. For a more traditional cream cheese flavor, reduce the butter to 1/2 cup, and add 1 block (8 oz.) of cream cheese. If using a full block of cream cheese, you can reduce the cream or milk to 1 tablespoon total.
Flavoring options- An almost unlimited number of flavoring options can be added in addition to, or instead of the vanilla. Orange and/or lemon zest, citrus extracts, mint extract, coconut extract or the seeds of a vanilla bean are all wonderful options. In most cases I'll still add 1/2 teaspoon of vanilla, then 1/2 teaspoon of the other flavoring. For zest, add about 1 teaspoon fresh zest. For chocolate buttercream, add 1/2 cup (good quality) unsweetened cocoa powder.
* In the bowl of an electric mixer, fitted with the whisk attachment, beat butter (on medium speed) until completely smooth (30 seconds to a minute). (If you are adding cream cheese, add it now, then beat until smooth)
* Add salt (if needed).
* One cup at time, add 2 cups of powdered sugar, beating after each addition.
* Add vanilla, or other flavorings and beat to combine.
* Add about 1 tablespoon of cream, and
* Add the remaining 2 cups powdered sugar, one at a time.
* Add an additional 1-2 tablespoons cream until desired consistency is reached. If you want to pipe the frosting on cupcakes, the frosting should be nice and thick. Continue to beat another minute or so. The frosting should now be smooth and fluffy.
* If your frosting is not smooth, it is likely because the butter was not fully smooth before adding the other ingredients.
* If your frosting will not hold up when piped on cupcakes, your frosting has too much liquid or is too warm. Put entire bowl of frosting in the fridge for 15-20 minutes and it will stiffen up. If it is still too thin, then add 1/4 to 1/2 cup powdered sugar, beat well.