Preheat the oven to 450°F.
In a large bowl, add flour, baking powder, and salt, and mix well.
Cut the cold butter into the flour mixture. Make sure flour looks like coarse crumbles + butter chunks are flat.
Add in the buttermilk and stir gently till combined. Fold-out dough onto a lightly floured surface. With flour-dusted hands, pat dough out into a rectangle. Fold the dough into thirds to stack the dough into three layers. pat out again and repeat the same process 1-2 more times (making sure you add flour between each layer, ensuring flaky layers).
Pat dough out until about 3/4 inch thick. Using a 2 1/2 - 3-inch circle cutter, gently cut out biscuits. Do not twist cutter, simply press down firmly.
Place the biscuit dough onto a cast iron. For soft sides, place biscuits with sides touching, or for crispier edges place 1 - 2 inches apart.
Bake in oven for 10 - 15 minutes, or until golden.