Prepare your ingredients. The water should be highly carbonated, then the dough will be very good. Melt the butter, chill a little.
Combine eggs, melted butter, yogurt, milk, sugar, salt in a mixing bowl. Whisk.
Add flour and baking powder. Combine all the ingredients, the mass should turn out smooth and without lumps.
Add sparkling water. Mix the dough well. Adjust the consistency of the dough with the amount of water, it should be thin, slightly thicker than the pancake dough.
Lubricate the hot waffle iron with vegetable oil (I do this with a silicone brush). Pour in the required amount of dough. Close the lid and cook for a few minutes. Remove the finished waffles with tongs.
Repeat the procedure for the rest of the test. Grease the waffle iron before each batch of waffles. Serve hot waffles with any filling: jam, condensed milk, syrup, berries or ice cream balls.