Preheat oven 350°F. Spray 8-1/2 x 4-1/2-inch loaf pan with baking spray.
Mix flour, baking powder, baking soda and cinnamon in medium bowl; set aside. Toss apples with oil in large bowl until apples are evenly coated. Stir in sugar. Add Egg Beaters and yogurt; mix well. Add flour mixture; stir just until moistened. Gently stir in cranberries. Stir in walnuts, if desired.
Spread batter evenly into prepared loaf pan.
Bake 1 hour, or until wooden pick inserted in center comes out clean. Cool in pan 10 minutes. Remove from pan; cool completely on wire rack. Cut into 14 slices to serve.