How do you make buttercream frosting?

Ingredients

* 1/2 cup shortening
* 1/2 cup butter, softened
* 1 teaspoon vanilla extract
* 4 cups confectioners’ sugar
* 2 tablespoons milk

Directions

1. In a large bowl, cream together the butter, shortening, and vanilla. Blend in
the sugar, one cup at a time, beating well after each addition. Beat in the
milk, and continue mixing until light and fluffy. Keep icing covered until ready
to decorate.

Prep time: 2 mins Cook time: 3 mins Total time: 5 mins
Serves: 2.5 cups

Classic American Buttercream frosting. This recipe uses powdered sugar, butter, vanilla and milk. This is a great recipe for decorating and piping on cupcakes and cake.
Ingredients
1 cup unsalted butter (2 sticks or ½ pound), softened (but not melted!) Ideal texture should be like ice cream.
3-4 cups confectioners (powdered) sugar, SIFTED
¼ teaspoon table salt
1 tablespoon vanilla extract
up to 4 tablespoons milk or heavy cream
Instructions
Beat butter for a few minutes with a mixer with the paddle attachment on medium speed. Add 3 cups of powdered sugar and turn your mixer on the lowest speed (so the sugar doesn’t blow everywhere) until the sugar has been incorporated with the butter. Increase mixer speed to medium and add vanilla extract, salt, and 2 tablespoons of milk/cream and beat for 3 minutes. If your frosting needs a more stiff consistency, add remaining sugar. If your frosting needs to be thinned out, add remaining milk 1 tablespoons at a time.

Source(s):
http://savorysweetlife.com/2010/03/buttercream-frosting/