Brush chicken with olive oil; sprinkle with 1/4 teaspoon salt and 1/2 teaspoon pepper. Coat romaine hearts with cooking spray, and sprinkle with remaining salt and pepper. Coat both sides of bread slices generously with cooking spray.
Place chicken, romaine, and bread on a grill rack coated with cooking spray. Grill chicken 7 to 8 minutes on each side or until done. Grill romaine halves 4 to 5 minutes. Grill bread slices 3 minutes on each side or until toasted.
Cut chicken diagonally into thin slices; cut grilled bread into large cubes. Arrange chicken strips and grilled croutons evenly over romaine halves; drizzle evenly with Caesar Dressing.