Pre-heat the oven to 100℃ (212℉).
Line a flat, large baking tray with baking paper.
Whisk the egg whites and maple syrup together until peaks begin to form.
Spoon out (or pipe) onto the prepared tray. You can make them as big or as small as you like. Mine were fairly large and I made 8 (see note 1).
Bake for two hours. Then, turn off the oven, and leave them inside for at least two more hours (I left mine overnight).
Enjoy on their own, or with your favourite dessert (see note 2).