Preheat oven to 400 degrees Fahrenheit. Grease an 8 x 8 inch baking dish and set aside.
Spray a 2 quart baking dish with cooking spray and set aside.
Whisk together the milk and the vinegar. Let sit for 5 minutes.
1 cup milk, 1 tablespoon white vinegar
In a large bowl whisk together the flour, cornmeal, sugar, baking powder, baking soda, and salt.
1 cup all purpose flour, 3/4 cup cornmeal, 1/3 cup granulated sugar, 3/4 teaspoon baking powder, 3/4 teaspoon baking soda, 1/2 teaspoon table salt
In another bowl whisk together the milk + vinegar, egg, and oil.
1 large egg, 1/4 cup vegetable oil
Gently fold the wet ingredients into the dry ingredients until just combined.
Pour the batter into the prepared pan. Bake for 25 to 30 minutes. At the end of the baking time, the center should be puffed up and bounce back when you push down on it gently. The edges will be golden and a toothpick inserted into the center of the bread (going all the way down to the bottom of the pan) will come out clean.
Allow to cool for 10 minutes in the baking dish. Remove and transfer to a wire cooling rack and allow to cool before cutting into large pieces for the stuffing, about 20 minutes.