Place tiger nuts and cinnamon stick in a large bowl and soak overnight.
Drain the tiger nuts and cinnamon stick, and discard the water. Then transfer the tiger nuts and cinnamon to a blender or food processor. Add the sugar and new filtered water, and blend until you obtain a smooth mixture.
Pour the milk mixture inside a nut milk bag and squeeze all the milk out. Transfer milk to a large glass container and refrigerate until ready to drink.