Cream butter & shortening. Add sugar. Add egg yolks. Mix together the flour and soda. Add the dry ingredients to the shortening mixture alternately with the buttermilk. Beat egg whites until stiff. Fold into the batter along w/ vanilla, coconut & pecans. Grease and flour 3 round cake pans. Pour batter into pans. Bake @ 350′F for 25 minutes. Let cool then decorate with icing.