In a bowl, mix flour, cornflour, and yogurt to make a smooth batter.
Add a pinch of baking soda and let the batter ferment for 8–10 hours or overnight.
Prepare sugar syrup by boiling sugar, water, and cardamom until slightly sticky. Add a few drops of lemon juice.
Heat oil or ghee in a pan for deep frying.
Fill the batter into a piping bag or squeeze bottle.
Pipe spiral shapes directly into hot oil and fry until golden and crispy.
Remove and immediately dip the jalebis into warm sugar syrup for 1–2 minutes.
Serve hot for the best taste.