Heat the oven to 425°F (220°C). Place a 10-inch cast-iron skillet in the oven as it heats.
Whisk cornmeal, flour, baking powder, baking soda, salt, and optional sugar in a large bowl. In another bowl, whisk buttermilk, eggs, melted butter, and optional honey.
Pour the wet mixture into the dry ingredients and fold just until no dry streaks remain. Do not overmix.
Carefully remove the hot skillet. Add 1 tablespoon butter and swirl to coat the bottom and sides. Pour in the batter; it should sizzle at the edges.
Bake 18 to 22 minutes, until the top is golden and a tester comes out with a few moist crumbs. Rest 5 minutes before cutting into 9 wedges.