Warm your Waffle iron. If you can choose settings I recommend doing darker for a crispier waffle. In a large bowl whisk the flour, baking soda, salt, and sugar then set aside.
Melt the butter in a small bowl, or measure out the vegetable oil. In a medium bowl whisk the milk, eggs and vanilla together. Stir in the melted butter or oil.
Add the wet mixture to the dry and mix until combined.
Add about 1/3 cup of batter for each waffle. This will depend on the size of your waffle maker so feel free to experiment with amounts. Place on a wire rack until ready to serve so they stay crisp.
MEASURING FLOUR: most of us won't break the kitchen scale out for breakfast and will use a measuring cup to scoop some flour out of the bag. If this is you then use two cups of flour. Give it a light fluff before scooping. If you are using a scale use 270g which is actually 2 1/4 cups. Sounds odd but after lots of recipe testing this is my best advice. Use a darker setting if possible. These waffles are best with a CRISP golden exterior.You can make a big batch of waffles and enjoy them for a few days afterwards. Wrap them up once they're room temp and place in fridge. Pop them into the toaster on a low setting and they'll be warm and crisp!Don't over-mix the batter. It's really just getting mixed until it comes together. If you see a few lumps don't worry. They'll disappear in the waffle iron.You can use a combination of butter and oil if desired, Oil gives crisp waffles but butter tastes great , I like to use 1/4 cup of each when I make these.