To make lemon frosting, combine 1/2 cup butter, 2 tablespoons lemon juice, 1/2 teaspoon vanilla extract and 2 cups confectioners' sugar in a mixing bowl. Beat the mixture with a mixer until light and fluffy. Add additional confectioners' sugar or lemon juice to adjust the consistency of the frosting as needed. This recipe makes 2 cups of icing.
Alternatively, make lemon cream cheese icing by combining 1 8-ounce package of cream cheese, 1/4 cup butter, 2 tablespoons lemon juice, 2 teaspoons lemon zest and 1 teaspoon vanilla extract. Beat the mixture until smooth and creamy. Add a total of 5 cups confectioners' sugar in two separate additions, beating until creamy. To adjust the consistency, add additional sugar or lemon juice. This recipe makes 3 2/3 cups of icing.
To make Wilton's lemon buttercream icing, start by creaming 1/2 cup vegetable shortening and 1/2 cup butter until fluffy. Add 2 tablespoons lemon juice and 1 teaspoon lemon zest, and beat well. Slowly add a total of 4 cups confectioners' sugar, one cup at a time, while beating on medium speed. Scrape down the sides of the bowl to ensure full incorporation of the sugar. Keep the frosting in the refrigerator, and cover it with a damp cloth when not in use.