Start by plugging your bubble maker in and getting it up to temp. While it's heating up, whisk together the yolks, vanilla, milk, butter, and sugar in a mixing bowl until well combined. Next, in a separate bowl, mix flour, baking powder, and salt together until incorporated. Then whisk the egg yolk mix into the flour mix until you have a smooth batter that is well blended.
The next step is to gently add the egg whites to the egg yolk mixture. Start by gently folding about a third of the egg whites (beaten into stiff peaks) into the batter. Then continue adding egg whites into the batter and folding until evenly combined.
Now that your batter is done, you're ready to make your waffles! It's important to make sure you coat your waffle maker with a non-stick spray before cooking. Some reviews suggest doing so before you heat up the waffle iron, but you do you. Begin by pouring about 3/4 c. of the batter into the waffle iron and close the lid. Next, flip the waffle iron over 180 degrees on both sides so that the batter can coat each of the bubbles. When the machine beeps, the waffles are done! If you want your waffles a little more crispy, then leave them in an additional minute past the timer. Last, remove with a spatula and set aside. You can turn these into tacos, waffle cones for ice cream, or whatever your heart desires!