In large mixing bowl combine shortening, butter, and vanilla. Mix until well combined and begins to lighten. This is easiest in a kitchen aid mixer, but a hand mixer can also work just might take longer.
Add one cup of powdered sugar, and 1 Tablespoon of milk. Beat until well combined and light. If need be scrap sides to make sure everything is mixed together.
Repeat with remaining sugar and milk, using 1 cup of sugar and 1 T of milk at a time. Once everything is incorporated make sure to continue whipping the frosting until texture is light and color lightens up. Frosting should end up light and fluffy.
Use as you would any other frosting. Enjoy.
The act of whipping this frosting does actually make a difference to the texture and taste. It’s like taking a canister of store bought frosting and beating it. You’d be amazed at the difference.