Mix the dry ingredients: Add the flour, sugar, baking powder and salt to a bowl. Stir very well until evenly mixed.
Mix the wet ingredients: MAKE SURE YOU SEPARATE THE EGGS! In a large measuring jug, whisk together the egg YOLKS, buttermilk, oil and vanilla extract until smooth.
Beat the egg whites: Beat the egg WHITES in a clean bowl with electric beaters until still peaks form. You'll know they're ready when you can slowly invert the bowl without the egg whites falling out.
Make the batter: Pour the wet ingredients into the bowl with the dry ingredients and stir a few times just to combine. Add the beaten egg whites and carefully fold in just until incorporated. Do NOT overmix, or the waffles will be dense.
Bake waffles: Preheat your waffle iron on medium-high. Lightly grease and bake waffles according to your manufacturer's instructions. I use about ¼ cup of batter per waffle, and I scoop it with a cookie scoop to make less of a mess.
Serve the waffles hot right out of the waffle iron - that's when they're the crispiest!
Oil: I prefer to use canola oil for these, as it is mild in taste and works great for cooking and baking. Feel free to use melted butter in place of the oil!
Buttermilk: If you don’t have any buttermilk on hand, use the same amount of regular milk with ½ tablespoon white vinegar stirred in. Let sit on the counter for 10 minutes, then stir again before using.
Flour: I use all-purpose flour for these waffles. You can also use half whole wheat and half all-purpose. If you want to use all whole wheat, I recommend substituting 2 tablespoons of the flour with cornstarch for a fluffier result. You will also need an extra tablespoon of oil and 1-2 extra tablespoons of buttermilk, as the whole wheat flour soaks up more of the liquid.
Batter:You'll want to do this very carefully, so you don't overmix the batter. Also fold in the egg whites gently, or you'll knock all the air out. But careful doesn't mean without determination, so don't be afraid to incorporate the egg whites. You'll want to take care there's no large clouds of unmixed egg whites left, otherwise you'll have flecks of scrambled egg white in your waffles.Baking:I never start preheating my waffle iron until the batter is done. Otherwise it stresses me out if I'm not ready yet. Do I have issues, you're asking? ha!I bake these on a medium-high setting and I lightly grease the waffle iron with a touch of oil before starting.How to know when waffles are done:When baking waffles in a waffle iron, it can be hard to judge when your waffles are done. It also tends to get hotter the longer it's on for, which means it's hard to even time.One little trick I use is this: I wait until there's no more wafts of steam coming out of the waffle iron. There will still be a little bit of steam, but you'll notice the first couple of minutes, there's a lot more steam! Wait for that to diminish before checking on your waffles.My theory behind this is that the wet ingredients in the batter create steam as they cook, so once that settles down the waffle should have firmed up enough to make it safe to check without destroying them.
Store cooled waffles wrapped in a clean kitchen towel at room temperature for up to a day.
To freeze: Place the waffles in a single layer on a lined baking sheet. Freeze for about an hour or until firm. Pack into freezer bags and label with the name and the date.To reheat: Pull out as many waffles as you need and reheat them in bursts in your toaster right out of the freezer. To reheat in the oven, bake the waffles on a rack for about 5-10 minutes at 360°F, or until hot and crispy.