Preheat your waffle maker according to the manufacture's instructions.
In a larger bowl, whisk together the following dry ingredients: flour, cornstarch, baking powder, baking soda and set aside.
In a medium bowl whisk together the sugar and the rest of the wet ingredients. Mix slowly to incorporate.
Pour wet ingredients into the dry ingredients. Using a silicon spatula fold until half of the flour is incorporated. Stir in blueberries. Mix slowly to combine all the ingredients. Do not over mix the batter. Small lumps in the batter are okay.
Spray your waffle maker with cooking spray or brush with melted butter. Depending on the size of your waffle maker you are going to fill it with batter. Read your waffle maker instructions. I used a 1/4 cup measuring cup for mine.
Close the lid and cook your waffle until golden and crisp. Cooking time will vary depending on your waffle maker. Read the manufacture's instructions for cooking time.