Preheat oven to 350°F. Spray 8-inch square pan with cooking spray.
Preheat grill or broiler to high. Slice bananas lengthwise and grill or broil them on one side for about 2 minutes. Set aside.
Heat olive oil in nonstick skillet, sauté onion and garlic until tender crisp, about 2 minutes. Add chicken, cilantro, cumin and coriander, sauté for 5 minutes. Add baby spinach, crushed tomatoes and olives, reduce heat and simmer for 5 minutes. Season with salt, to taste. Whisk together egg whites and thoroughly combine with chicken, set aside.
Layer half the banana slices in bottom of 8-inch square pan. Top with chicken mixture. Cover with half cheese, followed by another layer of bananas and finally top with remaining cheese. Bake 30 minutes or until cheese browns.