Add the milk, piloncillo, and cinnamon stick to a medium saucepan or pot. Warm over low-medium heat until the piloncillo has completely dissolved. Stir frequently to make sure the milk and piloncillo don’t stick to the bottom of the saucepan.
Remove and discard the cinnamon stick, using a strainer if it has broken into pieces.
In a small bowl, add the warm water and masa harina. Whisk together until smooth.
Add the masa harina mixture, vanilla extract, and salt to the saucepan. Whisk to combine.
Bring to a simmer, reduce heat to low, and continue to cook, stirring frequently, for 25-30 minutes until thick, creamy, velvety, and smooth. The atole should be thick enough to coat the back of a spoon.
Serve and garnish with a touch of ground cinnamon.
Notes
Don’t have piloncillo? You can use 1/2 cup of dark brown sugar instead.
Milk: Using whole milk is best since it provides a thicker and creamier texture and flavor, but you can use 2% as well if you prefer. You can also use almond milk to make this drink dairy-free.
Temperature: Make sure to heat the milk mixture over low-medium heat to ensure that the milk doesn’t burn.
Don't forget to whisk! Make sure to whisk vigorously throughout the whole process to help get the drink as smooth and velvety as possible. The atole should not be grainy. If it’s still a little grainy, continue whisking for a few minutes until it becomes smooth.