Preheat your oven to 450°F (230°C) and position a rack in the middle.

Combine the self-rising flour and cold butter in a large bowl. Use a pastry cutter, two knives, or your fingertips to cut the butter into the flour until coarse crumbs form with some pea-sized bits of butter remaining.

Pour in the full-fat buttermilk and stir gently with a fork or spatula until the dough just comes together. The mixture should be slightly shaggy and moist; do not overmix.

Turn the dough onto a lightly floured surface and fold and press it gently 3–4 times to form a cohesive mass. Avoid overworking the dough to prevent tough biscuits.

Pat or roll the dough to about 1 inch thick. Use a biscuit cutter to cut the biscuits without twisting. Re-roll scraps only once.

Place the biscuits on a baking sheet, slightly apart for tender sides or touching for taller biscuits, and bake for 12–15 minutes until golden brown. Rotate the pan once if needed.

Remove from the oven and serve warm. Optionally, brush the tops with melted butter.