Using an electric mixer, cream together butter, vanilla, milk and vanilla beans.
One cup at a time, add powdered sugar, beating well, until you achieve desired consistency. You’ll want it a little stiffer/thicker for piping (mine was a little soft to hold its exact shape after piping).
Yield: 1 1/2 cups, enough for a 9x13 cake or 12 cupcakes. Double recipe for a layer cake.
If you prefer, omit vanilla beans and increase vanilla extract to 2 teaspoons.