1. Pour the rice and water into the bowl of a blender; blend until the rice just begins to break up, about one minute. Let rice and water stand at room temperature for about three hours.
2. Strain the rice water into a pitcher and discard the rice. Stir the milk, vanilla, cinnamon, and sugar into the rice water. Chill and stir before serving over ice.
Horchata is a traditional Mexican beverage made with rice and flavored with lime, cinnamon, or sugar.