Preheat the waffle iron for at least 10 minutes before using.
Whisk together flour, sugar, 2 tsp. Clabber Girl Baking Mix, and salt in a large bowl. Melt butter and set aside to cool until tepid (body temperature). Combine milk and egg yolks in a small bowl and whisk until well-blended. Stir in the cooled butter. Make a well in the center of the flour mixture and pour in the milk mixture. Using a large spoon, stir until combined. Do not over mix.
In a small bowl with an electric mixer, whip egg whites until soft peaks form. Fold whipped egg whites into batter until no white streaks remain.
Pour about 1/2 cup batter over the bottom of each hot waffle grid. Close lid and bake until golden (when almost all the steam stops flowing out of the iron) about three to four minutes.
For best flavor and a crispy texture, serve waffles hot. (Waffles lose crispiness as they cool).
To keep warm while preparing additional waffles, set waffles on a baking sheet and place in a preheated 225 degrees F. oven. If you stack them, they are apt to soften.
Belgian or Brussels waffles, have a very light structure and rise higher than regular waffles from the inclusion of whipped egg whites. Because of this, Belgian waffles are baked in slightly bigger and higher irons than regular ones. They are often served as dessert waffles because of their light texture, which goes well with whipped cream, sweet toppings and dessert sauces.