Iced Horchata Latte

Using a spice mill or coffee grinder, coarsely grind rice and transfer to a 2-qt. airtight container. Coarsely grind coffee beans and place in same container as rice. Add almonds, cinnamon stick, and 4 cups water. Cover and let soak in refrigerator overnight. Bring sugar and 1/4 cup water to a boil in a small saucepan, swirling pan occasionally to dissolve sugar, about 3 minutes. Transfer simple syrup to a heatproof container; cover and chill until cool, at least 30 minutes. Transfer rice mixture to a blender and blend until very smooth. Strain through a fine-mesh sieve into a medium bowl, pressing on solids to extract as much liquid as possible. Sweeten latte to taste with simple syrup and add salt. Serve over ice.