Step 1

Position a rack in the middle of the oven and preheat to 450 degrees. Add the butter to a 9-inch square baking dish or 9-inch cast-iron skillet and place in the oven while it preheats. (If your oven is very slow to heat up, wait a few minutes to put in the baking dish so the butter doesn’t burn. Just keep an eye on it as it melts.)

Step 2

In a large bowl, whisk together the flour, baking powder, sugar and salt until combined. Add the buttermilk and stir gently with a spatula just until combined. Do not overmix.

Step 3

Remove the hot baking dish or skillet from the oven and gently pour the batter over the melted butter. Use a knife or offset spatula to spread the batter evenly in the dish or skillet.

Step 4

Quickly and confidently, use a knife to “cut” the dough into 9 squares (they’ll have round edges in the skillet). If the lines close up, go back and take another pass through, though you shouldn’t expect them to remain completely distinct. It can help to wipe or rinse off the knife in between cuts.

Step 5

Bake for 20 to 25 minutes, rotating the pan halfway through, or until the tops of the biscuits are golden brown and the edges crisp. Following your scored lines, cut and serve.