Preheat the oven to 80°C Fan, 100°C electric, 212°F, or gas mark 1/4.
Slice the apples into very thin slices, discarding the cores. A mandolin is best for this.
Lay the slices out on parchment-lined baking trays. I used three.
Sprinkle generously with cinnamon and pink sea salt (if using).
Place them in the oven and bake for approximately 2 hours, 45 minutes. Check them roughly every 45 minutes. The end result should be crispy apple chips. If they are still soggy, they need to be dried out more.