Preheat oven to 350°. Coat 9-inch square pan with nonstick cooking spray. In a large mixing bowl, combine the flour, 1 cup sugar and baking powder. Add egg whites and vanilla. Mix well. Fold in apples and nuts. Spread into pan. Combine cinnamon and 2 teaspoons sugar; sprinkle over the top. Bake for 30 to 35 minutes, or until a toothpick inserted near the center comes out clean.