Preheat the oven to 250 degrees Fahrenheit. Place two large oven safe cooling racks on top of two large baking sheets.
Peel the apples and slice into thin slices, less than ¼ inch thick but thicker than a coin. Place the slices in a single even layer on top of the racks on baking sheets. Transfer the baking sheets to the oven and bake for about 45 minutes.
Meanwhile, in a shallow dish, whisk together the remaining ingredients. Remove the apple slices from the oven and place in the dish. Let marinate for 10-15 minutes. Remove the apple slices from the marinade, letting the excess drip off, and return to the lined baking sheets in a single even layer.
Return the baking sheets to the oven and bake for 60 to 90 minutes, or until light brown in color and firm to the touch. Depending on how thick the apples are sliced, some pieces may be crispy before others and there will be a variety of textures. Immediately remove the apple slices from the racks and allow to cool in a single even layer on another surface. The slices will crisp up further after cooling.
Enjoy inside sandwiches, on top of salads, or by themselves!