Combine the water, butter, salt, and lemon zest in a small saucepan and bring to a boil. Stir in the rice and return to a boil. Reduce the heat to medium low, cover, and simmer for 20 minutes.

Use a paring knife to scrape the beans from the vanilla pod. In a large saucepan, combine the milk, sugar, vanilla beans and pod, and cinnamon. Bring just to a boil, and then stir in the cooked rice. Simmer the mixture on medium heat, stirring constantly, until milk is reduce and pudding is thickened, about 20 minutes. Remove the vanilla bean pod.

Serve warm or cold, with a sprinkling of cinnamon, if desired. Store in the refrigerator.