Add buttermilk mixture and sifted ingredients to creamed mixture. Fold in 4 egg whites whipped stiff but not dry. Spread 1/2 batter in well greased large bundt or angel food pan. Sprinkle 1/2 sugar and cinnamon. Spread in remaining batter and sprinkle rest of sugar. Run knife through to marblize. Bake 55 minutes at 350 degrees. Makes yummy muffins, too!