Bring 4 cups of water to a boil. Add 8 Tadin Canelita tea bags to boiling water, cover and steep for 5 min. Remove bags and let tea cool to room temp (the freezer or fridge will help expedite this step).
While tea cools, rinse the rice and add it to a blender. Add 2 cups of cooled tea to blender and pulse to coarsely grind. Pour contents of the blender into a bowl and top with the remaining 2 cups of Canelita tea. Let sit at room temp for 3 hours.
After 3 hours, add rice mixture to blender and blend until smooth. Strain through a fine mesh sieve, stir in sugar and chill until cold. Before serving, stir well, pour over ice and garnish with a cinnamon stick.