Preheat oven to 350°.
Bring broth to a boil; pour over cornmeal in a large bowl. Stir and let stand 5 minutes.
Place 1 cup corn, milk, and next 7 ingredients in a blender; process until smooth. Whisk together corn mixture and cornmeal mixture; stir in remaining corn and cilantro.
Beat egg whites with a mixer at high speed until stiff peaks form; fold egg whites into cornmeal mixture. Spoon mixture into an 11 x 7-inch baking dish coated with cooking spray. (Dish will be very full but will not bubble over.)
Bake at 350° for 45 to 50 minutes or until puffed and golden. Remove from oven; let stand 10 minutes before serving.