Spray a lg skillet w/ cooking spray, place over medium heat. Spread butter onto 1 side of 2 slices of bread. Arrange apple slices on unbuttered sides of bread. Sprinkle apple w/ cinnamon. Place cheese slices on top of apples. Top w/ remaining bread. Butter top-side of bread. Gently place sandwiches in skillet. Cook for 3-5 min on both sides, or until golden brown and cheese is melted.