Preheat oven to 350 degrees. Prepare a loaf pan with parchment paper or grease with non-stick spray.
In a mixing bowl, add corn flour, all-purpose flour, salt, and baking powder. Using a fork or a whisk stir to combine and set aside.
In another bowl and using a whisk or an electric hand mixer beat sugar with eggs until combined. Gradually add oil, milk, and vanilla if using.
Pour mixture into prepared loaf pan or muffin tin. Bake for about 35 minutes depending on your oven. Make sure to use an oven thermometer to check if your oven's temperature is accurate.
Use a toothpick or butter knife to check that it has cooked through. If it comes out clean, the cornbread is done.