Preheat your oven to 90∞Celcius
Line 3 baking racks (not tins as you need the heat to circulate)
Using your apple corer/knife carefully remove the core from the 3 apples and pop in a bowl of water to prevent browning
Finely slice the apples (as thin as possible) – again keep all sliced apples in a bowl of water until slicing is complete (you may need a second bowl for this)
Spread all the slices on your baking tray and evenly sprinkle the cinnamon on top (I used a small sieve to do this)
Place your baking trays in the oven leaving space between the trays
Bake for approximately 2.5 hours, opening the oven every 15 minutes to release any gas and turning/switching the trays every 30 minutes
When ready they should be nice and crispy
Remove from oven and leave to cool for 10-15 minutes and you’re ready to serve (they’re delicious with peanut butter!)