Sift All-Purpose Flour (1 1/2 cup), Baking Powder (2 teaspoon), Salt (1/2 teaspoon) and Granulated Sugar (3 tablespoon) into a large bowl.
Put the yolks of the Egg (3), Milk (1 cup), Unsalted Butter (4 tablespoon), and Pure Vanilla Extract (2 teaspoon) into another bowl and beat well.
Lightly stir in the flour mixture until just about blended.
Place the egg whites into a clean bowl and beat with a wire whisk, or electric mixer, until stiff peaks form. Gently fold the beaten egg whites into the batter with a large spoon.
Lightly brush the inner surface of each pan with a small amount of melted butter or neutral oil. Preheat the outside of both pans on the stove over medium heat.
Fill the indentations of one pan just until the batter is level and attach the other preheated pan by the handy hinge. Flip the whole thing over halfway through cooking.
The waffles should take about two to three minutes per side, depending on your stove. The interior surface is nonstick, so the waffles should release from the pan without a problem.
Sprinkle with a dusting of Powdered Confectioners Sugar (to taste) if desired. Serve immediately with maple syrup.