Preheat oven to 350°. Spray 6-cup Bundt pan with non-stick cooking spray. Set aside.
Combine flour, baking powder, baking soda and salt in large bowl. Combine sugar, buttermilk, eggs substitute and oil in medium bowl. Add sugar mixture to flour mixture; stir just until moistened.
Fold in raspberries and blueberries. Pour batter into prepared pan. Bake 1 hour or until wooden toothpick comes out clean. Cool in pan on wir rack. Serve with additional berries and whipped cream, if desired.