In a large mixing bowl, combine the flour, baking powder, sugar, and salt.

Add the melted butter, egg, and warm milk. Mix until a soft dough forms.

Knead the dough on a floured surface for about 5 minutes until smooth and elastic. If the dough is too sticky, add a little more flour.

Cover the dough with a clean kitchen towel and let it rest for 15 minutes to relax the gluten, making it easier to roll out.

Divide the dough into 12 equal portions.

Roll each portion into a thin disc, about 6 inches in diameter.

In a deep frying pan or pot, heat the vegetable oil to 350°F (175°C). Use a thermometer to ensure consistent frying temperature.

Carefully place one dough disc into the hot oil. Fry for 1–2 minutes per side until golden and crisp.

Use tongs or a slotted spoon to remove the buñuelo from the oil, and place it on a plate lined with paper towels to drain excess oil. Repeat with the remaining discs.

In a small bowl, mix the sugar and cinnamon.

While the buñuelos are still warm, coat them generously in the cinnamon-sugar mixture.