Preheat a waffle maker so it is hot when you are ready to cook the waffles.
In a large bowl, whisk the flour, sugar, baking powder, baking soda, and salt.
2 cups all-purpose flour, 2 Tablespoons granulated sugar, 1 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon salt
In a separate bowl, whisk the buttermilk, melted butter, eggs, and vanilla extract.
2 cups buttermilk, 6 Tablespoons salted butter, 2 large eggs, 1 teaspoon vanilla extract
Add the buttermilk mixture to the flour mixture, stirring by hand with a large spoon just until combined. It's okay for the batter to be lumpy.
Spray the waffle maker with cooking spray so the waffles won't stick. Pour the batter onto the waffle maker. Keep in mind that the batter will expand when you close the waffle maker and try not to overfill. Close the lid and cook for 3 to 5 minutes until the waffles are golden brown and crisp on the outside. Transfer the finished waffles to a wire rack while you cook the rest of the batter.