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. Stir together until just combined.
Allow batter to rest for 30 minutes.
Preheat oven to 200°F or set it to the warm setting and set a baking sheet (with cooling rack if you have one) inside.*
After the batter has rested, fold in the chocolate chips.
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.
Transfer waffle to your warm oven while you cook the rest of the batter.*
Top with melted butter and syrup if desired, and enjoy!