Blend one cup of jasmine rice until it is pulverized. If you are soaking your rice over night, you can skip this step.
Add 4 cups of hot water and two cinnamon sticks. Give it a good shake/stir, then let it sit for 1-2 hours or until the water is cool enough to touch.
Blend until smooth, about 2 minutes.
Strain through a triple-layered cheese cloth AND a fine mesh strainer. This step is very important- you do not want a grainy horchata!
Squeeze out all the liquid, then discard the remaining grains.
Add the evaporated milk and condensed milk and stir well.
Strain the horchata again. You may see a lot of grains settled at the bottom of the bowl while pouring it into the strainer- try not to add those bits. Taste the horchata- if it still has a grainy texture that leaves your tongue dry, strain again. I strongly dislike when horchata is grainy. Strain as many times as you need to!
When you've strained enough, add the sugar. I like my horchata on the sweet side- if you don't like it that sweet, start with 1/4 cup of sugar. Optional: add 1/2 tsp of vanilla extract. I stopped adding vanilla extract to my horchata, I don't think it's necessary but you can add it if you want :)
The horchata will be too thick at this point, so you'll need to add some water. For me, 3 cups of water is perfect. Just remember to keep your horchata slightly thicker than you want it, because it will water down a bit more once you serve it over ice.
Refrigerate the horchata for up to 5 days. I recommend having it with lots of crushed ice :)