Source: original recipe from Jamie's America by Jamie Oliver
adapted by http://theresalwaysthyme.blogspot.com

3/4 cup long-grain rice
1 quart whole milk (I used 1% milk)
1 teaspoon ground cinnamon
1/4 cup light brown sugar
1 or 2 cinnamon sticks

Prepare the rice according to the package instructions, then strain and run under cold water so it cools down quickly. Put the cooled rice into a blender with the milk, ground cinnamon, and sugar. Blend until smooth, then taste and add more sugar, if it needs it.

Strain rice mixture into a pitcher with ice. Discard the rice. Snap cinnamon sticks in half and place into pitcher with the horchata. Pour into glasses. Sprinkle over a little more ground cinnamon and serve.