1. In medium bowl combine Kellogg's® Complete® Wheat Bran Flakes cereal, flour, baking powder, 1 teaspoon cinnamon and salt. Set aside.
2. In large mixing bowl, beat butter and 3/4 cup sugar on medium speed of electric mixer until thoroughly combined. Add egg whites and vanilla, beating until smooth. Beat in half of the cereal mixture. Add milk; mix well. Beat in remaining cereal mixture. Stir in apples. Spread batter evenly in 8 x 8 x 2-inch baking pan coated with cooking spray. Sprinkle with 2 tablespoons sugar and 1 teaspoon cinnamon.
3. Bake at 375°F about 25 minutes or until toothpick inserted in center of cake comes out clean.