In a medium mixing bowl beat shortening, vanilla, and extract with an electric mixer on medium speed for 30 seconds. Slowly add half of the powdered sugar, beating well. Add 2 tablespoons of the milk. Gradually beat in remaining powdered sugar and enough remaining milk to reach spreading consistency. This frosts the tops and sides of two 8- or 9-inch cake layers. (Halve the recipe to frost a 13x9x2-inch cake.) Makes about 3 cups.