Heat the oven to 320°F (160 °C). Wash the apples and cut out the cores without cutting them into slices.
Then slice them very thinly - into 1/16 slices.
Sprinkle them with the cinnamon and arrange in a tray covered with baking paper ahead of time.
Bake 45-60 min., turning them from time to time.
The apples need to bake until they get a nice crisp. Cool and serve like chips.