White Cake

INGREDIENTS
2 cups white sugar
2 cups sifted all-purpose flour
3 egg yolks
1 egg
1/2 cup buttermilk
1 teaspoon vanilla extract
1/2 teaspoon salt
1 teaspoon baking powder
1 teaspoon baking soda
1/2 cup shortening
1 cup boiling water
DIRECTIONS
Mix together the buttermilk with the baking soda. Set aside. Cream shortening, sugar, eggs and vanilla. Beat well.
Add buttermilk and baking soda mixture.
Sift dry ingredients, and add to creamed mixture.
Add boiling water, and mix well.
Pour into a greased and floured 9 x 13 inch pan. Bake at 350 degrees F (175 degrees C) for approximately 35 minutes, or until toothpick comes out clean.