Chill the ingredients

• Place the bowl in the refrigerator and the flour in the freezer so everything is as cold as possible.

Combine the flour and butter

• Add the self-rising flour to the cold bowl.
• Grate the frozen butter into the flour.
• Mix with a fork until the butter is coated.

Add the buttermilk

• Pour in the buttermilk a little at a time, as you may need more or less.
• Mix until the dough comes together.

Fold the dough

• Turn the dough out onto a clean, dry surface dusted with flour.
• Fold the dough over itself 5 to 7 times to build layers.
• Pat the dough to about 1 inch thick.

Cut out the biscuits

• Dip a glass in flour and push straight down without twisting.
• Lift the cutter straight up to release each biscuit.

Bake the biscuits

• Place the biscuits in a buttered cast iron skillet.
• Brush the tops with buttermilk.
• Bake at 450 °F (230 °C) until golden, broiling 1 to 2 minutes if needed to brown the tops.