In a large pot, combine the milk, piloncillo, Mexican chocolate, and whole cinnamon stick. Heat over low-medium heat, stirring frequently to make sure nothing sticks to the bottom of the pan, until the piloncillo and chocolate have completely dissolved.

Meanwhile, in a large bowl, whisk together the warm water and masa harina until smooth.

Once the piloncillo and chocolate have dissolved, add the masa harina mixture, vanilla extract, and salt to the pot and whisk to combine.

Bring to a simmer, then reduce the heat to low. Cook, whisking frequently, until thick, creamy, velvety, and smooth, 20-25 minutes. The champurrado should be thick enough to coat the back of a spoon.

Remove and discard the cinnamon stick from the champurrado, then serve and enjoy!

In a large bowl, mix together the flour, baking powder, and salt to combine. Add the warm water and 4 tablespoons of oil, using a spoon or your hands to mix the ingredients until the dough comes together.

Transfer the dough to a clean work surface and knead until smooth and elastic, 8-10 minutes.

Roll the dough into a ball and place it in a bowl. Cover the bowl with a clean kitchen towel and let it rest for 20-30 minutes.

While the dough rests, line a large plate with paper towels. Fill a large rondeau or high-sided pan with 2-3 inches of frying oil.

In a small bowl, mix together the sugar and cinnamon to combine; set aside.

Divide the dough into 12 equal-sized pieces, then roll each piece into a ball. On a lightly floured surface, use a floured rolling pin to roll out each ball into an 8-inch circle.

Heat the frying oil to 350°F. Working in batches as needed, add the dough circles to the hot oil and fry, turning halfway through, until golden on both sides, about 1 minute total.

Immediately transfer the buñuelos to the paper towel–lined plate to drain any excess oil, then sprinkle heavily with cinnamon-sugar topping and serve.