Beat together the first 5 ingredients in an electric mixer until combined.
While continuing to beat, drizzle in the milk, one tablespoon at a time until the frosting becomes light and fluffy and achieves your desired consistency.
Recipe by MomOf6 at https://www.momof6.com/food-kids-will-eat/the-best-fluffy-frosting-recipe-for-cakes-cupcakes-cookies/