Preheat your waffle iron according to manufacturer's instructions.
In a large bowl, whisk together flour, baking powder, salt, and sugar.
Separate eggs, placing whites in a clean bowl.
Mix egg yolks, milk, oil, and vanilla in another bowl.
Beat egg whites until stiff peaks form.
Pour wet ingredients into dry ingredients, mixing until just combined.
Gently fold in beaten egg whites until incorporated.
Cook waffles according to your waffle iron's instructions until golden brown.