
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.