This is what Alton Brown calls Buttercream Icing
Buttercream by Alton Brown
Show: Good Eats
Episode: The Icing Man Cometh
4 eggs, room temperature
1/2-cup dark corn syrup
10 ounces butter, cubed and at room temperature
In a large mixing bowl, whip the eggs until light and fluffy.
In a small saucepan bring the sugar and the corn syrup to a boil. Lubricate the inside of a metal baster with a small amount of vegetable oil and dispense it completely. Then use this to drizzle the sugar mixture into the mixing bowl with the eggs. The mixer should be on low speed until you finish drizzling in all of the sugar mixture.
Once the entire mixture of the sugar is incorporated, slowly add the butter pieces. Only add more butter when you can no longer see the previously added pieces. It will go fast at first and then slow down. Continue to whip until the mixture is creamy.
This is what I call Buttercream Frosting.
Butter Cream Frosting
1 stick butter (1 stick = 1/2 cup)
1 pound powered sugar
Allow butter to soften slightly, place in a large bowl with milk, salt, vanilla, and about half the sugar.
Mix slowly so that sugar doesn't fly everywhere. Gradually add the rest of the sugar.
Beat on high speed until the mixture is light and fluffy. It will be an off-white color and creamy. Cover the frosting with a damp towel until you're ready to use it.
This is what Wilton calls Icing.... I don't like this recipe because there is too much fat in it.... In my opinion you might as well sit down with a spoon and dig into a can of shortening.Wilton: Recipe Box: Buttercream Icing
1/2 cup solid vegetable shortening
1/2 cup butter or margarine, softened
1 teaspoon Clear Vanilla Extract
4 cups sifted confectioners' sugar (approx. 1 lb.)
2 tablespoons milk
In large bowl, cream shortening and butter with electric mixer. Add vanilla. Gradually add sugar, one cup at a time, beating well on medium speed. Scrape sides and bottom of bowl often. When all sugar has been mixed in, icing will appear dry. Add milk and beat at medium speed until light and fluffy. Keep bowl covered with a damp cloth until ready to use. For best results, keep icing bowl in refrigerator when not in use. Refrigerated in an airtight container, this icing can be stored 2 weeks. Rewhip before using.
YIELD: Makes about 3 cups.
For thin (spreading) consistency icing, add 2 tablespoons light corn syrup, water or milk.
For Pure White Icing (stiff consistency), omit butter; substitute an additional 1/2 cup shortening for butter and 1/2 teaspoon No-Color Butter Flavor. Add up to 4 tablespoons light corn syrup, water or milk to thin for icing cakes.
There is at least one more recipe that I know of that uses egg whites that is called a Frosting.... I don't happen to have the recipe where I can lay my hands on it but if you do a google search for Italian Style Buttercream Frosting I think you will find the recipe.