Add the milk, piloncillo, Mexican chocolate, and cinnamon stick to a medium saucepan or pot. Heat over low-medium heat until the piloncillo and chocolate have completely dissolved. Stir frequently to make sure nothing sticks to the bottom of the saucepan.
Remove and discard the cinnamon stick. You may need to use a strainer if it has broken into pieces.
In a small bowl, whisk together the warm water and masa harina until smooth.
Pour the masa harina mixture into the pot along with the vanilla extract and salt. Whisk to combine.
Bring to a simmer, reduce heat to low, and continue to cook, whisking frequently, for 15-20 minutes until thick, creamy, velvety, and smooth. The champurrado should be thick enough to coat the back of a spoon. For an extra velvety texture, blend the champurrado with an immersion blender to get it super smooth.
Serve and garnish with a touch of ground cinnamon or a cinnamon stick.
Notes
Milk: Using whole milk is best since it provides a thicker and creamier texture and flavor, but you can use 2% if you prefer. You can also use almond milk or another milk alternative.
Don’t have piloncillo? You can use ¼ cup of dark brown sugar instead.
Cinnamon stick: I recommend using a Ceylon cinnamon stick, sometimes referred to as Mexican cinnamon. This is the kind that’s brittle and can be easily broken in half. You can find it in Mexican grocery stores or online. However, a regular cinnamon stick (Cassia cinnamon) is okay to use as well.
Don't forget to whisk! Make sure to whisk throughout the whole process to help get the drink as smooth and velvety as possible. The champurrado should be completely smooth and not grainy. You could also use an immersion blender if you have one to make it really smooth without having to use all your arm strength. It’s a great substitute for a molinillo which is traditionally used when making this Mexican drink.
Too thick? Champurrado will thicken as it cools. If it thickens too much, mix in a warm milk as needed.
Make this dairy-free. Use almond milk, cashew milk, soy milk, or your favorite milk alternative.