To a blender, add rice, 2 cups of hot water, and 2 Mexican cinnamon sticks.

Blend until the rice and cinnamon sticks are roughly ground. Add the remaining water and blend again.

Pour contents into a pitcher or container with a fitted lid and refrigerate overnight or for at least 8 hours.

Pour the rice mixture through a fine mesh strainer or cheesecloth, into a pitcher. Discard the rice.

Stir in the milk, vanilla, cinnamon, and sugar (to your preference). Chill until ready to serve. Stir well before serving and serve over ice.