2 tsp. baking soda
1 c. buttermilk (or sour milk: 1 tbsp. vinegar + milk to equal 1 cup)
3/4 c. butter, softened
1 2/3 c. sugar
1 egg
1 tsp. vanilla
1/2 tsp. salt
2 c. unsifted all-purpose flour
2/3 c. unsweetened cocoa
3/4 c. sour cream

Stir baking soda into buttermilk or sour milk; set aside. Cream butter and sugar in a large mixing bowl until light and fluffy; blend in egg, vanilla and salt. Combine flour and cocoa; add alternately with buttermilk or sour milk mixture and sour cream to creamed mixture. Beat well.

Pour into 2 greased and floured 9-inch layer pans. Bake at 350 degrees for 30 to 35 minutes or until cake is done. Cool and remove from pans. Frost with Chocolate Butter Cream Frosting.