Combine the water, rice, cinnamon sticks, and salt in a large pot or Dutch oven over medium-high heat. Bring to a boil, reduce heat to low, cover, and cook for 15 minutes.
Stir in the milk and sugar. Bring to a boil, reduce heat to low, and cook for 25-30 minutes, stirring often until thickened.
Serve warm or refrigerate for 2 hours and serve cold.
Garnish with ground cinnamon, chopped nuts, or raisins if desired.
Video
Notes
Milk: Whole or 2% milk is recommended. I don't recommend using skim/nonfat milk. This recipe has not been tested using a milk alternative like almond, soy, oat, or cashew milk, though I'm sure it would work!
Mix-ins: If you'd like to add in a mix-in like raisins or other dried fruit, I recommend adding it when you add in the milk.
Storage + Freezing: It can be stored in an airtight container in the fridge for 5-6 days. You can also freeze it in a freezer-safe container for up to 3 months. Just be aware that the texture may change slightly when reheated.
Reheating: It is best reheated in a pot on the stove or in a bowl in the microwave. You may need to add a splash of milk or water since it will have thickened in the fridge.