Soak the rice in the water for 45 minutes. Drain, pulse rice in a food processor 4-5 times. In a large bowl, add the chopped rice, coconut milk, cinnamon, and 6 cups of lukewarm water, let stand for 1 hour. Strain the mixture through a fine sieve. Add the sugar; stir unit it is dissolved and chill. Serve in large tumblers with lots of ice. Sprinkle with additional cinnamon, if desired.

Serving glass: Large Tumblers