In a large bowl, whisk together flour, corn starch, sugar, baking powder, baking soda, and salt.
Make a shallow well in the dry ingredients and add buttermilk, vegetable oil, egg, and vanilla, and stir together until just combined.
Allow batter to sit for 30 minutes.
Preheat oven to 200°F and set a baking sheet inside to place the waffle(s) on after cooking to keep warm while you cook the rest of the batter.*
Preheat waffle iron and cook batter according to your iron’s instructions*, typically 4 to 6 minutes per waffle, until waffle is nicely golden and has mostly stopped releasing steam. Waffle may not initially seem crispy to the touch, but will crisp up out of the waffle maker.
Top with melted butter and syrup if desired, and enjoy!