Stir together the dry ingredients into an ungreased 8" x 8" or 9" x 9" pan. Make three holes in sifted ingredients. Put vanilla in the first hole, cooking oil in the second hole and vinegar in the third hole. Pour 1 cup lukewarm water over the whole thing. Stir well with a fork. Bake 30 to 35 minutes at 350 degrees F or until top springs back when touched slightly.