Heat the cream, zest, and cinnamon in a saucepan to boiling. Remove from the heat and let steep 2 hours.
Heat the chocolate in a small heavy pan over low heat until melted. Continue cooking, stirring constantly, until it is “scorched” and thick, about 3 minutes. Transfer to a large mixing bowl.
Strain the cream into another saucepan and reheat to boiling. Whisk the egg yolks and