Directions
Set a rack in the middle of the oven and put a 10-inch cast-iron skillet on it. Heat the oven to 425°F and let the skillet heat for 5 minutes.
Whisk the cornmeal, flour, sugar, baking powder and salt in a large bowl.
In a second bowl whisk the buttermilk, eggs and 4 tablespoons of the melted butter until smooth.
Pour the wet mixture into the dry and stir just until combined. A few lumps are fine.
Carefully remove the hot skillet. Add the remaining 2 tablespoons of butter and swirl to coat the bottom and sides, then scrape in the batter and smooth the top.
Bake 18 to 22 minutes, until the top is golden and a toothpick in the center comes out clean. Cool in the pan for 5 minutes before slicing.
Tip
Do not skip the hot skillet; it is what gives the bottom its crust. A 9-inch square pan works too, but the crust will be softer.
Storing
Wrap cooled cornbread and keep at room temperature for 2 days, or freeze up to 2 months. Rewarm in a 350°F oven.
Swaps
No buttermilk: stir 1 tablespoon of lemon juice or vinegar into 1 cup of milk and let it stand 5 minutes. Check ingredient labels if you cook for someone with an allergy. See the Disclaimer.