Whip the sugar with the eggs until fluffy - the volume should increase and the mixture turn pale.

Add the baking soda, vanillin, salt, sour cream, and melted butter, continuing to whip.

At the end, sift in the flour and whip for another couple of minutes - the batter is ready.

Heat the waffle iron, brushing it with vegetable oil. Spoon about 1 tbsp of batter into the center and close the iron.

Bake for about 5 minutes, checking periodically, until golden on both sides. Dust with powdered sugar - ready to enjoy!