Optionally rub both sides of apple slices with sugar and cinnamon. This isn't necessary (the apples are plenty sweet), but it does make them look better because the sugar caramelizes and the cinnamon just works perfectly with apples.
Place one apple slice in each section of the waffle iron.
Close the waffle iron and cook for about a minute or until the apples look waffled.
Repeat until you are out of apple slices. Serve warm.