Put the rice in a large bowl. Then break up the cinnamon stick into pieces and add it to the bowl as well.
Pour in 6 cups of water and cover the bowl. Let soak for at least 4 hours or overnight.
Transfer half of the soaked mixture along with half the water used for soaking to the blender and blend for about a minute.
Then strain into a pitcher using a fine mesh strainer.
Next, pour in the can of evaporated milk, sweetened condensed milk and the rest of the soaked mixture to the blender and blend for another minute. Then strain into the pitcher. Discard the solids left behind in the strainer.
Now add the remaining 6 cups of water and the vanilla to the pitcher. Stir well.
Transfer to the refrigerator to chill or serve immediately over ice. Enjoy!