In a large bowl, combine flour, sugar, baking powder and salt.
In a separate bowl, whisk the melted butter, egg, and vanilla. Add the wet ingredients to the dry ingredients, and mix well until the mixture is crumbly. Slowly add the water a tablespoon at a time, mixing and kneading until you have a soft and smooth dough formed in a ball.
Cover and let the dough rest for 30 minutes.
While the dough is resting, line a plate with paper towels and heat a large cast-iron skillet with oil over medium-high heat.
Use a dough scraper to divide the dough into 12 balls.
On a lightly floured surface, use a rolling pin to roll out each ball into a thin 6-inch circle without breaking the dough. Repeat with the remaining dough.
Fry dough circles, one at a time, until puffed and golden (about 30-45 seconds on each side). Place on paper towel-lined plate and sprinkle with cinnamon sugar while hot.