Heat coals or gas grill. Place chicken breast halves between 2 pieces of
waxed paper. Pound chicken to 1/8-inch thickness. Mix sugar and cinnamon.
Coat apple slices with sugar mixture. Divide apple slices among chicken
breast halves. Fold chicken around apples; secure with toothpicks.

Cover and grill chicken 4 to 6 inches from medium heat 20 to 25 minutes,
turning once, until juice is no longer pink when centers of thickest
pieces are cut. Remove toothpicks.

Mix apple cider and cornstarch in 1-quart saucepan. Cook over medium heat,
stirring constantly, until thickened and bubbly. Spoon over chicken.