Heat oven to about 300 degrees.
Put butter in a 9x13 baking dish. Place in oven until butter is melted.
When you remove the melted butter, turn oven to 385 degrees.
Mix together white sugar with butter, and then beat eggs in until blended.
Mix together baking soda and buttermilk, and mix into the dish.
Add cornmeal, flour, and salt and mix until everything is combine.
Bake for about 30 minutes, or until toothpick comes out clean.