Add 1 cup white rice to a blender or food processor and grind it as fine as you can.
Add 3/4 cup raw almonds, 1 cinnamon stick, 1/4 cup sugar and 4 cups of warm water. Blend together.
Let this mixture sit overnight in the fridge (or at least for a few hours).
The next day, give it another blend and then add 1.5 cups coconut milk. Combine well and taste for sweetness, adding more sugar if you want.
Strain the mixture and discard the leftover solids. Using a fine mesh sieve works but you can also add a few layers of cheesecloth to it if you want.
If using a popsicle mold, fill the mold with the Coconut-Horchata mixture but leave a little space at the top for room to expand while freezing. Place the mold in the freezer for an hour or so and then insert the popsicle sticks (it's easier to get them to stay in place once partially frozen). They'll need another few hours in the freezer to completely freeze.
To remove them from the mold, let them sit on the counter for a few minutes or run some water over the mold. Serve immediately and store leftovers in a Ziploc in the freezer.