Sift all the dry ingredients into a large bowl
Place the butter into a small microwavable bowl and microwave until melted, then let it cool down
Add the milk and the yolks and mix well
In a separate bowl, place the egg whites and add a sprinkle of salt, then whisk with an electric whisk to until you have stiff peaks
Add the wet mixture into the dry mixture, mix well
Then slowly add the egg whites. Let the batter rest while you heat up your waffle maker
Scoop the batter into the waffle maker, and cook for a few minutes until ready. Enjoy warm