In a large saucepan, bring the cider, 2 cinnamon sticks, the cloves, nutmeg and lemon peel to a simmer over medium-high heat. Lower the heat to medium- low and cook, without boiling, for 15 minutes.
Remove from the heat and stir in the calvados, if using. To serve, pour into mugs and garnish each with 1 of the remaining cinnamon sticks.
