In a blender, grind dry rice until very fine
Transfer rice to a medium size mixing bowl, pour hot water over rice, add cinnamon stick cover and refrigerate overnight
Remove cinnamon stick, blend mixture until smooth
Strain liquid through a fine sieve lined with cheesecloth, squeeze liquid from cheesecloth and discard the remaining solids
Add sugar and milk, stir until sugar is dissolved
Refrigerate until very cold, pour over ice cubes and garnish with ground cinnamon, and cinnamon sticks
For the spiked version, add ½ jigger of Mexican Rum