Make the buñuelo dough
Add the flour, baking powder and salt to a mixing bowl and mix to combine.
2 C All-Purpose Flour, 1 1/2 tsp Baking Powder, 1/2 tsp Salt
Add the hot water and 4 Tbsp of butter/oil, to the flour mixture. Mix this into a dough with your hands. Continue mixing in the bowl until the dough comes together and gets less sticky.
4 Tbsp Melted Butter or Vegetable Oil, 3/4 C Hot Water
Transfer the dough onto a floured surface and knead it for 10 minutes. It should gain some elasticity and easily form into a ball. Note: it can be pretty sticky to start. Just re-flour your hands and the surface as necessary until the dough comes together. Divide the dough into 8 equal-sized pieces and roll the pieces into balls. Place them into a bowl, cover them with a slightly damp towel, and let them rest for at least 15 minutes (preferably 30).
Make the (optional) syrup
In a small sauce pot, combine the piloncillo, (optional) cinnamon stick and water. Heat over low heat (to just barely a simmer), stirring occasionally. The piloncillo will melt into the water, forming a syrup. Continue cooking to your desired thickness (I recommend just thinner than pancake syrup) and then cut the heat. Note: this can cook while you fry the buñuelos.
1 Cinnamon Stick, 3/4 C Water, 1 8 Oz. Piloncillo
Fry the Buñuelos
Prep for frying while the dough rests. Start by mixing the sugar and ground cinnamon in a small bowl. Set aside.
1/2 C White Sugar, 1 Tbsp Ground Cinnamon
Line a plate with paper towels. You will put the buñuelos here after frying to drain off excess oil. Have a second plate ready to place the drained buñuelos on.
Finally, heat your frying oil to 350 degrees in a wide pan or pot. You need the pan to be at least 10 inches wide and tall enough to hold the depth of your oil, plus at least 6 inches more. You need at least 3/4" oil for frying. Up to 2 inches in depth will do well (any more and you are basically wasting oil). In measuring the temperature of the oil, I recommend a kitchen thermometer or probe. If you don't have one, you can also throw a pinch of flour into the hot oil every few minutes or so. If the flour floats and bubbles, it is ready to fry. Note: using the flour method may lead to variations in frying time because you don't know the exact oil temperature. 2-4 C Vegetable Oil for Frying
Once the oil is hot and the dough has rested, roll one of the balls out onto a lightly floured surface. Roll, with your rolling pin or wine bottle, until the dough is nearly transparent (around 1/8th inch thick). Turn as you roll, so the ball flattens into a round disc (like a tortilla).
Once flat, carefully add this disc to the hot oil, laying it down away from you to avoid splashes. Tongs may help here. Note: Don't worry if the disc folds on itself. It will want to straighten out. Just nudge it a bit with the tongs to help it along. Fry the disc for 2 minutes, flipping halfway through, or until it is solid and golden (time may vary if you don't know your oil temperature). It will form bubbles as it fries. Try not to break them.
Once fried, remove the disc from the oil, being sure to let excess drip off, and place it on your paper-towel lined plate to drain (you will have to flip it once to let the second side drain). As it drains on the first side, roll out the next dough ball and begin frying it.
Right before the next dough disc finishes frying, add the draining disc to the second plate and sprinkle both sides liberally with the cinnamon sugar mixture. Once coated, pour the excess cinnamon sugar back into the bowl so you can top the rest of the buñuelos.
Repeat the rolling, frying, draining and sugar-sprinkling steps until all of the buñuelos are fried and coated in sugar. If you have extra cinnamon sugar left over, get it on those buñuelos!
You can serve these buñuelos right away while they are warm. Pour the (optional) syrup over them just before serving, or use it for dipping.