Slice your apples as thinly as you can. Don't bother to core them, but do remove seeds and stems from the slices.

Arrange in a single layer on a cookie sheet, using parchment paper or a silicon mat.

Sprinkle your apple slices generously with cinnamon and bake at 225 degrees for 2.5-3 hours, turning sheet around halfway through cooking time. (Note: If using a mandoline to slice more thinly, this might take 2 hours or less.)

Test for doneness around the 2.5 hour mark, and when apple slices are lightly browned and crisp and the edges are curling up, turn off the heat and leave them in the oven another half hour to an hour or so to finish drying out.

Remove from cookie sheet and enjoy!

Store any leftover apple chips in a tightly sealed container and use within a couple of days.