2/3 c. medium or long-grain rice (preferably organic)
1 1/4 c. blanched almonds
3-inch piece cinnamon stick, preferably Mexican canela
2 1/2 c. hot tap water
1 c. sugar, plus more as needed
2 c. cold water
In a large bowl, combine the rice, almonds, cinnamon stick and hot water. Let cool, then cover and refrigerate overnight.
Pour the mixture into a blender, add the 1 c. sugar and blend on high speed until smooth, 3 to 4 minutes. Line a chinois or other fine-mesh sieve with cheesecloth and set over a clean bowl. Pour the mixture through the sieve and press on the solids until only a dry pulp remains. Pour the liquid into a pitcher, add the 2 cups cold water, taste and add a little more sugar, if needed. Pour into ice-filled tall glasses.