Bake for a second hour and pull a single chip out of the oven and set it down to cool for a few minutes. If it crisps up, pull the rest, If it doesn't crisp up, test another chip in ten minutes.
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Notes
Store in an airtight container for up to three days. If the chips get soggy, you can re-crisp them at 200 F for about 20 minutes.You can leave off the sugar if your apples are really sweet. You can also experiment with other spices like pumpkin pie spice or gingerbread spice.