Preheat oven to 400° and grease an 8-inch square baking pan or a cake pan with the 1-2 tablespoons of Vegetable oil. Place pan in oven while it heats.
Toss blueberries with 1 teaspoon of flour and set aside.
Combine flour, cornmeal, sugar, baking powder, and salt in a large bowl. Stir with a whisk to evenly combine ingredients.
In a medium bowl, combine egg, milk, vegetable oil, and vanilla extract. Whisk well.
Add wet ingredients to dry and mix just until dry ingredients are moistened. Gently fold in blueberries. Pour batter into prepared pan and bake for 20-25 minutes or until a wooden pick inserted in the center comes out clean.