Place 1 cup of milk in a saucepan, add cinnamon sticks and lemon peel. Over medium heat, bring milk to a simmer.

Whisk together cornstarch and sugar in a small bowl. Once mixed, add remaining milk.

When the milk in the pan starts to simmer, add cornstarch mixture. Whisk vigorously while increasing heat to a gentle boil. Do not stop whisking.

Still keep whisking, but allow to boil for 20 seconds. Remove from heat. Now you can stop whisking.

Remove lemon peel and cinnamon sticks. Stir in ground cinnamon and vanilla.

Pour into mold and refrigerate for at least 6 hours.

Garnish with shaved or grated chocolate before serving.