Preheat oven to 400°F (200°C).
In a large mixing bowl, whisk together flour, cornmeal, salt, baking soda, and baking powder.
In a separate bowl, whisk together buttermilk, egg, and melted butter.
Add the wet ingredients to the dry ingredients and stir until just combined. The batter should still be slightly lumpy.
Pour the batter into the prepared baking dish or cake pan.
Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
Remove from oven and let cool for 5-10 minutes before slicing and serving.