In a heavy-bottomed saucepan, combine the water, butter, salt, and zest. Bring to a boil, then stir in rice and return to a boil. Cover and simmer over very low heat for 15–25 minutes, until the water is absorbed. The heat can be shut off just before the water is gone.

In a 3-quart saucepan, combine milk, sugar, and vanilla bean and bring to a simmer over low heat. Do not boil. Add rice mixture and raisins and simmer for about 20 minutes, stirring frequently, until most of the milk is absorbed and the rice is creamy. Transfer the pudding to a glass, ceramic, or metal bowl and sprinkle with cinnamon. Cool to just warm and serve.