Preheat oven to 375 degrees Grease an 8 inch square pan.
Melt butter and add to a mixing bowl. Stir in sugars until well combined. Add eggs and stir well, until combined.
Combine buttermilk with baking soda and stir into the bowl.
Add cornmeal, flour, and salt and stir until combined. Avoid over-mixing--the batter doesn't need to be completely smooth.
Pour batter into the prepared pan. Bake at 375 degrees for 22-30 minutes, or until a toothpick inserted in the center comes out clean.
*Buttermilk substitution- if you don't have buttermilk, no problem! Add one tablespoon of white vinegar or lemon juice to a liquid measuring cup, then fill the cup with milk to the 1 cup line. Storing: Leftover cornbread can be stored in an airtight container at room temperature for up to one week. (It will dry out the longer it sits out, so I think it's best enjoyed the day of baking.)Freezing Instructions: You can freeze cornbread in an airtight, freezer safe bag or container for up to 3 months. Thaw in the refrigerator overnight and rewarm gently in the microwave. Variations:
Muffins: fill the muffin cups 2/3 full. Bake at 400F for 15-20 minutes. I especially love to freeze cornbread muffins, so that I can easily grab one and pop it right in the microwave for a few seconds.
Corn Flour or Polenta: I would not recommend substituting either corn flour or polenta for the cornmeal in this recipe! The cornmeal is a star ingredient that gives the bread it's unique texture and flavor.