In a large pot, combine the water and cinnamon stick. Bring to a simmer with the lid on for a few minutes. In the meantime, rinse the rice until the water runs clear.
Add the rice to the pot of water and bring the mixture to a low boil. Turn the heat down to low and simmer with the lid on for 10-12 minutes, or until the rice is tender and the water has mostly absorbed.
Remove ½ - ¾ of the rice (depending on your texture preference) and add it to a blender. Add the soy milk and sugar to the pot with the rest of the rice.
Ladle some liquid out to help mix the rice in the blender. Combine until smooth, then transfer the mixture back to the pot.
Simmer for an additional 8-10 minutes, stirring frequently. Taste and adjust the sugar to your preferred sweetness.
Serve your atole while warm with a sprinkle of cinnamon or berries on top. Serve on its own or with your favorite pastry. Happy drinking!
Notes
Blend the cinnamon: If you prefer a cinnamon-forward atole, blend the whole cinnamon stick with the rice.Blender safety: When blending hot ingredients, allow the steam to escape periodically to prevent pressure buildup in the blender.Skip the blender: Many atole de arroz recipes skip the blending and instead keep the rice grains whole. Try it out and see what you think!The key is to simmer the rice just enough so it's tender but not mushy. Overcooking the rice at this stage can lead to an atole that is too thick.Nutritional information is a rough estimate and should not be taken as health advice.