1 cup butter (2 sticks or ½ pound), softened (but not melted!)
3 to 3 1/2 cups confectioners (powdered) sugar
1/4 teaspoon table salt
2 teaspoons vanilla extract
4 tablespoons milk or heavy cream (use only if needed to reach desired consistency)
Directions
Cream butter for a few minutes in a mixer with the paddle attachment on medium speed. Turn off the mixer. Add 3 cups powdered sugar into the mixing bowl. Turn mixer on the lowest speed until the sugar is absorbed by the butter. Increase mixer speed to medium and add vanilla extract and salt. Beat for 3 minutes. If your frosting needs a stiffer consistency, add a little more sugar. If your frosting needs to be thinned out, add milk 1 tablespoon at a time.
Notes
If you want chocolate frosting, add 1/2 cup cocoa powder