Preheat oven to 350F. Sift together flour, baking powder, salt and cocoa. Mix oil, sugar and eggs (one at a time). Add food coloring to eggs; mix well. Combine buttermilk and baking soda; add to oil mixture. Alternating with dry mixture, add vinegar and vanilla. Mix well. Turn into greased layer cake pans or 9 x 13 inch pan.
Mix all ingredients, spread on cake.
Cajun Country -- New Iberia, Louisiana