In a large mixing bowl, whisk together the all-purpose flour, baking powder, and salt until well combined.
Add cold butter pieces to the flour mixture. Use a pastry cutter, your hands, or a food processor to work the butter into the flour until the mixture resembles coarse crumbs.
Gradually pour in the buttermilk while mixing gently with a wooden spoon or rubber spatula. Mix until a sticky dough forms.
Turn the dough out onto a lightly floured surface and gently roll into a rectangle about 1/2 to 3/4 inch thick.
Use a 2-inch biscuit cutter or a drinking glass to cut out biscuits. Place them on a greased cast iron skillet or a parchment-lined baking sheet.
Bake in a preheated 425°F oven for 15 minutes or until the tops are golden brown.
Remove from the oven and brush the tops with melted butter. Serve warm with your favorite toppings.
Notes
Store leftover biscuits in an airtight container at room temperature for up to 2 days or freeze in a freezer bag for longer storage.