In a large mixing bowl, combine all-purpose flour, baking powder, baking soda, salt, and sugar. Create a well in the center and add the egg and vegetable oil. Gradually mix until a shaggy dough forms.

Transfer the dough to a lightly floured surface or use a stand mixer. Knead on low speed for about 7-9 minutes until soft and slightly elastic. Cover and let it rest for 1 hour.

Roll the dough into a rectangle approximately 1 cm thick. Brush the surface with vegetable oil, cover, and let it rest for another 1-2 hours. Cut into strips measuring about 3 cm wide.

Take one strip of dough and use a wet chopstick to create a line down the center. Place another strip on top and press the seams to seal.

In a deep pot, heat vegetable oil to between 180-190°C. Monitor the temperature closely.

Once hot, stretch each strip before sliding them into the oil. Fry for about 1 minute, continuously rolling until golden brown. Drain on a wire rack.