Heat oven to 400°F. Spray 9-inch square pan with nonstick cooking spray.
Lightly spoon flour into measuring cup; level off. In large bowl, combine flour, cornmeal, baking powder and salt; mix well. Add all remaining ingredients; stir just until well mixed. Spoon batter evenly into spray-coated pan.
Bake at 400°F. for 18 to 23 minutes or until center is firm to the touch and toothpick inserted in center comes out clean. Cut into squares. Serve warm.