In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt, and granulated sugar.
In a separate bowl, whisk together the yogurt and egg until well combined.
Add the wet ingredients to the dry ingredients and mix until a soft dough forms. If the dough is too sticky, add a little more flour.
In a deep frying pan or pot, heat about 2 inches of vegetable oil over medium heat until it reaches 350°F (175°C).
Using a spoon or your hands, drop small balls of dough (about the size of a golf ball) into the hot oil. Fry in batches, turning occasionally, until golden brown and cooked through, about 3-4 minutes per batch.
Remove the fried petulla with a slotted spoon and drain on paper towels to remove excess oil.
Enjoy your meal!