In a large bowl, whisk together the flour, baking powder, and salt.

Add the cold, cubed butter to the flour mixture. Use a pastry cutter, fork, or your fingertips to work the butter in until it looks like coarse crumbs with some pea-sized bits of butter remaining.

Pour in the buttermilk and stir gently, just until the dough comes together. Be careful not to overmix.

Turn the dough out onto a lightly floured surface. Pat it into a rectangle about 1 inch thick. Gently fold the dough over onto itself 2 times to create layers. Pat it back down to about 1 inch thick.

Use a floured biscuit cutter to cut out biscuits, pressing straight down without twisting. Place them close together in a well-buttered 10-inch cast-iron skillet (or another baking dish if needed).

Put the biscuits on a small baking tray and pop in the fridge or freezer while the oven preheats to 450ºF. This helps keep the butter cold for extra fluffy biscuits.

Place biscuits close togther in a greased cast iron pan. If you’d like, brush the tops of the biscuits with buttermilk or an egg wash (1 egg beaten with a splash of water) for a golden, shiny top.

Bake for 15 minutes on a low rack, then move them to an upper rack for 3 more minutes, or until the tops are golden and the biscuits are tall and fluffy.

Allow to sit on the counter for 10 minutes, then serve right from the skillet while they’re still warm, or place them in a bread basket and cover with a napkin, just like Grandma did.