Dan's Buttercream
Dan: 
 
Our favorite American buttercream recipe makes the perfect filling and frosting for your cakes!
Ingredients
  • 1 pound of unsalted butter, softened
  • 1.75 pounds of 10x powdered sugar (sift if there are any lumps)
  • 3-4 tablespoons of skim milk
  • 2 teaspoons of quality vanilla extract
  • ⅛ teaspoon of table salt (dissolve in milk)
Instructions
  1. Beat the butter in a stand mixer until it is creamy and slaps the sides of the bowl. Scrape your bowl. Add 3 tablespoons of milk and extracts and blend slowly until combined. Raise speed to medium and beat to form a smooth butter mixture.
  2. Add half of the powdered sugar and blend on low until combined. Scrape bowl, add the remaining sugar and set the mixer to medium low (speed 2 on a Kitchenaid) and blend for 2-3 minutes.
  3. Resist the urge to add more milk right away because the buttercream will thin out as it mixes.
  4. After mixing on low for 2-3 minutes you can choose to add more milk, 1 teaspoon at a time, to reach your desired consistency.
  5. Scape your bowl and then set the mixture to medium low (speed 2 on a Kitchenaid) and mix for 10 minutes. You may scrape the bowl half way through.
  6. Frosting can be made softer with the addition of milk, ½ teaspoon at a time. Will keep for 3 days at room temp, or 2 weeks refrigerated.
Notes
Buttercream Variations:
Add ½ cup marshmallow fluff to finished buttercream.
Stir in a generous amount of chopped oreos for a delicious cookies and cream filling.
Add up to ½ cup of creamy peanut butter to finished buttercream.
Add 2-3 ounces of melted and cooled bittersweet baking chocolate to finished buttercream.
Dissolve 2-4 teaspoons of instant espresso powder into your vanilla extract for coffee buttercream. Also works with the melted chocolate for mocha buttercream.
Eliminate vanilla extract and add up to 2 teaspoons of peppermint, lemon, orange, coconut or almond extracts. You may choose to add a few drops of vanilla just to round off the flavor.

Other Notes:

*When making this recipe for cakes with a buttercream finish, it is best to double it. This will make a batch of icing that completely fills a 5 quart Kitchenaid mixer bowl. A doubled batch should fill the bowl beyond the beater leaving your resulting icing smooth and fairly free of air bubbles. Adding the liquids before the sugar and mixing only on a low speed prevents the formation of pesky air bubbles that cause problems when trying to frost a buttercream cake smoothly. It is important to mix the icing for the full 10 minutes in the final step. However, if you would prefer a fluffier aerated icing for cupcakes or cakes you can simply raise the mixer speed to medium and beat the icing for 4-5 minutes.

*In warm weather, when piping flowers or peaked designs, consider replacing 25% of the butter with a quality shortening such as Crisco.
Recipe by Baking With Dan at https://www.bakingwithdan.com/dans-buttercream/