Melt butter and let it cool

In a large bowl, whisk together flour and baking power.

In a small bowl, whisk together the egg yolks and milk. Add to the flour mixture along with the butter and mix until all tge dry ingredients are wet.

Using an electric mixer, beat egg whites until stiff peaks form. Gently fold egg whites into the batter.

Heat waffle iron for at least 5 minutes

Cook each waffle until most of the steam has stopped coming out of the machine, about 5 minutes.