1Heat oven to 200°F. Line cookie sheet with cooking parchment paper; spray paper with cooking spray.
2In small bowl, mix sugar and cinnamon. Place apple slices on cookie sheet. Spray apples with cooking spray; sprinkle evenly with sugar-cinnamon.
3Bake 2 hours, rotating cookie sheet after 1 hour. After 1 hour 30 minutes, check apples every 10 minutes to avoid burning. Store in airtight container.