Wash and drain rice. Combine rice with cinnamon sticks in water and soak overnight in the refrigerator.
After the rice has soaked for at least 8-10 hours, preferably overnight, discard the cinnamon sticks and pour rice and water into a blender. Add ½ tsp cinnamon and blend on low for 2-3 minutes until well blended. Pour blended rice mixture through fine mesh sieve two times and then through cheesecloth one more time to remove all gritty bits of rice.
Pour strained mixture into a pitcher, add skim milk, brown sugar and vanilla and stir well to combine. Add more sugar if needed, to taste. Best served with ice & a dash of ground cinnamon.