Mix together the sugar and cinnamon in a small bowl. On one sheet of apples, sprinkle the cinnamon and sugar over the tops of the apples. On the other baking sheet of apples, spread the tops with maple syrup. (Can also double cinnamon and sugar and skip maple syrup or use only maple syrup - your preference!) Place both baking sheets in the prepared oven and bake for 1 1/2 hours. Flip apples over and continue baking for 1 more hour, until the apples are crispy. Let cool and store in an airtight container. Enjoy!