Wash and drain the rice. 

Using a spice grinder (an electric coffee grinder works well too), grind the rice until fine; combine with the almonds and cinnamon bark. 

Add 3½ cups water and let sit overnight, covered. 

Blend rice-almond mixture until smooth using a blender. Add 2 cups of water and continue blending. 

Add sugar and vanilla extract. 

Strain horchata into a bowl with a fine mesh sieve (I used a chinois).  I don’t have a great blender, so I then put the pulp back through with 2 more cups of water and strained again.

This should last in your fridge about 2 days.  Use any extra to make Popsicles (just pour into pop molds and freeze - you might want to make these a bit sweeter as it loses some of the flavor when frozen)

Nutrition note - This drink is overall very healthy and the less sugar you use the better, but I am not including the full information because it is hard to calculate considering all that is filtered out.  Without filtering it is around 250 calories, so it should be considered a nice snack and considering the protein and fiber is a pretty good one.