Horchata is originally from Spain and dates back to the Moorish invasion, more than a thousand years ago. In Spain, horchata has always been made with chufa or tiger nuts and even has its own denomination of origin.
1 cup cashews
1 cup brown rice
½ Mexican cinnamon stick
4 tablespoons shaved piloncillo or brown sugar, plus more to taste
4 cups water
In a deep container, combine the cashews, rice, cinnamon stick, 4 tablespoons sugar, and the water. Cover and refrigerate for at least 8 hours and up to overnight.
Transfer all of the ingredients to a blender and blend until smooth. Strain the mixture through a fine-mesh sieve (discard the solids). If desired, add more sugar to taste. Serve over ice.