Preheat your oven to 425°F (220°C).
In a large bowl, whisk together the flour, baking powder, baking soda, and salt until well combined.
Grate the cold butter directly into the flour mixture. Gently toss or mix until the butter is evenly distributed and the mixture resembles coarse crumbs.
Pour in ¾ cup of cold buttermilk and stir just until a shaggy dough forms. Add more buttermilk a tablespoon at a time if the dough seems too dry.
Lightly flour a clean surface and transfer the dough onto it. Gently pat and fold the dough over itself 12–14 times to build layers.
Flatten the dough to about 1-inch thickness and use a round biscuit cutter or a cup to cut out biscuits.
Lightly oil or spray a cast iron skillet or baking pan. Place the biscuits close together for softer sides or spaced apart for crispier edges.
Bake for 15–18 minutes, or until the tops are golden brown.
Brush the hot biscuits with melted butter as soon as they come out of the oven.
Serve warm and enjoy!