Line a baking tray with grease proof paper and heat your oven to 160°C.
Whisk the egg whites until they form stiff peaks.
Add to the rest of the ingredients.
Using a spatula or metal spoon, mix the ingredients together. (Avoid using a wooden spoon or over-mixing as it will bash all the air out of the egg whites).
Wet your hands slightly and with a wet palm roll around 20-40 balls and place them on your baking sheet. They don’t spread too much when baked so you can fit quite a few on a tray. Pop them in the oven for 18 minutes.
Remove the tray from the oven. Place the icing sugar in a bowl and while the cinnamon balls are still warm roll them around until coated all over and leave to cool completely.