Preheat the oven to 400 degrees F. Whisk cornmeal, flour, sugar, baking powder, baking soda, and salt together in a large bowl.
In a small bowl, whisk the butter, eggs, and buttermilk until well blended. Pour this mixture into dry ingredients and gently stir until just combined.
Generously grease an 8” baking pan. Pour batter into prepared pan and bake for about 20 minutes, or until a toothpick inserted in the center of the bread comes out clean.