Preheat the oven to 400F. Grease a cast iron skillet for ease of lift.

Sift the cornmeal, flour, baking soda, baking powder, and salt through a fine mesh strainer into a large bowl.

In a smaller bowl, whisk together the cooled melted butter and brown sugar until well combined. Add the eggs and whisk until barely combined so as not to burn the eggs.* Add the buttermilk and while until fully combined.

Create a well in the dry ingredients. Pour the wet ingredients into the well and stir with a wooden spoon or rubber spatula. Try not to overmix. A few small dry pockets is okay.

Pour the batter into the prepared skillet and bake for 20 minutes. The edges should be a darker brown in color and start to pull away from the skillet. The center will be golden brown, firm, and spring back when touched.

Allow to cool before cutting and serving as this gives the gluten time to solidify and the cornbread to hold its shape.