Preheat the oven to 400 degrees F (200 degrees C). Grease an 8 inch glass baking dish.
Sift the flour, cornmeal, sugar, baking powder, baking soda and salt into a large bowl. In a separate bowl, whisk together the buttermilk, corn oil and egg. Pour the wet ingredients into the dry ingredients, and mix just until blended. Pour into the prepared pan, and shake gently to level it out.
Bake for 30 minutes in the preheated oven, or until a knife inserted in the center comes out clean and the top is golden brown. Serve hot. Just with butter will do, it is plenty sweet enough!