1Mix together the buttermilk with the baking soda. Set aside. Cream shortening, sugar, eggs and vanilla. Beat well.
2Add buttermilk and baking soda mixture.
3Sift dry ingredients, and add to creamed mixture.
4Add boiling water, and mix well.
5Pour 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.