Preheat oven to 400 degrees F. Butter an 8" cast iron skillet or an 8 X 8 baking pan
In a medium mixing bowl, combine flour, cornmeal, sugar, baking powder, baking soda, and salt.
Add milk, egg, and melted butter and mix well
Pour into prepared pan and bake for 20-25 minutes. Cornbread is done when a toothpick or a cake tester comes out clean.