grease and lightly flour 2 8" round cake pans -- or 1 9x13" pan.
In bowl, mix flour, soda and salt.
In large mixing bowl, beat Crisco with mix about 30 seconds add sugar and vanilla till well combined.
Add egg yolks 1 at a time, beating well after each addition, alternating with flour mixture and buttermilk to Crisco, beat on low speed just till combined.
Wash beaters well. In a medium bowl, beat egg whites on medium till soft peaks form.gently fold whites with beaten mixture -- spread into prepared pans.
Bake at 350° for 30-35 minutes for 8" cake rounds or 35-40 for 13 x 9 pan or until toothpick inserted near the center comes out clean.
Cool on rack in pan for 10 minutes.remove from pans to cool completely.
ICING: (frost and fill layers, cover and store in refrigerator up to 3 days. Let stand at room temperature 30 minutes before serving.
To prepare icing -- mix 1 cup milk with 1/4 cup flour.cook and stir till bubbly -- reduce heat -- cook and stir for 2 minutes. Transfer mixture to a small bowl, cover surface with plastic wrap, chill 2 hours. In large mixing bowl, beat 1 cup butter, 1 cup granulated sugar and 1 tsp vanilla till fluffy and sugar is almost dissolved -- add cooled cooked mixture, 1/4 amount at a time -- beat till smooth.