1. Preheat oven to 350°F. Spray 10-inch (12-cup) bundt pan with nonstick cooking spray; flour lightly.
2. In medium bowl, combine 3 cups flour, cornmeal, baking soda, baking powder and salt.
3. In large bowl, combine granulated sugar, milk, sour cream, apple sauce, whole egg, oil and vanilla.
4. Add flour mixture to apple sauce mixture; stir until well blended. Gently fold in beaten egg whites.
5. In small bowl, combine brown sugar, apple, oats and cinnamon.
6. Spread half of batter into prepared pan; sprinkle with oat mixture. Spread remaining batter over oat mixture.
7. Bake 60 to 70 minutes or until toothpick inserted in center comes out clean. Cool on wire rack 15 minutes before removing from pan. Place cake, fluted side up, on serving plate. Serve warm or cool completely. Cut into 24 slices.