- In a medium bowl, combine 2 1/2 cups of the water, cashews, rice, and cinnamon. Refrigerate, covered, overnight. After ingredients have soaked overnight, pour into the bowl of a blender and add agave nectar and 1 more cup of water.
- Blend until all ingredients are blended thoroughly, about 30 seconds. Strain into a medium bowl through a fine mesh sieve or nut milk bag. Squeeze out the remaining liquid from the pulp. Stir in remaining 1/2 cup of water.
- Serve in glasses rimmed with cocoa sugar (dip rims of glasses in horchata before rimming with sugar blend).