In a large saucepan, combine water, sugar, cinnamon stick, and lemon zest. Cut the vanilla bean in half lengthwise, scrape out the seeds, and add both the seeds and pod to the pan. Over high heat, bring the mixture to a boil and stir occasionally, until the sugar is completely dissolved.

Peel the pears. Bring the poaching liquid down to a simmer over low-medium heat. Add the pears and cook until tender, about 15 minutes. Remove the pan from the heat and allow the pears to rest in the poaching liquid until completely cooled, approximately 45 minutes.

Heat the heavy cream in a small saucepan over low heat. Add the chocolate to a bowl and pour the heavy cream over the chocolate chips. Let rest for one minutes and stir to combine.

Serve each pear with a drizzle or dollop of sauce.