Preheat oven to 350° F. Sift together flour, cocoa, salt and soda. Cream together shortening, sugar, eggs and vanilla until light and fluffy.
Add vinegar and food coloring to buttermilk. Add dry ingredients alternately with buttermilk to creamed mixtures. Mix until well blended. Pour batter into greased and waxed paper lined 9x13x2 baking pan.
Bake for 40 minutes.
Servings: