Sieve the flour into a large bowl with the salt and baking soda.
Separate the eggs and beat the yolks until they become light in color and fluffy.
Add the sugar and butter to the egg yolks and mix well.
Whisk the egg whites until they form stiff peaks.
Add the milk and dry ingredients to the egg yolk mixture gradually, alternating between the two.
Fold in the egg whites gently. Bake in small batches in your waffle iron.