Bring 2 cups of water to a boil in a saucepan. Once boiling, add the cup of rice and let it cook for about 5 to 7 minutes over medium heat. Turn off the heat and let it cool.

Pour the entire contents of the evaporated milk and sweetened condensed milk cans into a blender.

Add the rice with the cooking water and the cinnamon stick. Blend until the rice and cinnamon are completely dissolved.

Strain the mixture into a 5 or 6-quart pitcher.

Once everything is strained and in the pitcher, add ice to taste and fill with water to make 5 or 6 quarts.

Taste and add sugar depending on how sweet you like it. Serve and sprinkle ground cinnamon in the glass.