In a large bowl whisk together your flour, baking powder, sugar, and salt.
Add in your egg, melted butter, and vanilla. Mix until it resembles a coarse meal. Add your water in 1 tablespoon at a time, mixing and kneading until your dough is soft and completely smooth, this should take 3-4 minutes. Cover the dough with saran wrap or a kitchen towel and let it rest for 30 minutes.
Prepare a flat surface with a rolling pin, a plate with paper towels, flour for dusting, bench scraper or knife. On the stove in a large frying pan, heat your vegetable oil to 350℉ (over medium high heat). Your oil should only be about 1- 1.5” deep so the amount of oil you use will vary depending on the size of pan you’re using.
Once the dough has rested, put it onto your work surface and cut into 12 equal balls. Flour your working surface and begin rolling out each ball into a thin circle. You want your bunuelo to be as thin as possible without tearing it. The dough should be almost transparent.
Once all your bunuelos are all rolled out and ready, you can fry them in the hot oil until they are golden and crispy, this should take about 60 seconds, and they should be flipped halfway through frying.
As you remove the bunuelos from the frying oil, once they are done cooking, place them on the paper towel lined plate to absorb any excess oil. When all the bunuelos are done, you can sprinkle them with cinnamon sugar and enjoy!