Preheat oven to 425. Sift flour, baking powder, sugar and salt into a large mixing bowl. Transfer to a food processor. Cut frozen butter into cubes and add to flour, then pulse 6 or 7 times until it looks like a loose crumble. Place the dough back in the bowl, add buttermilk and stir with a spatula until it forms a rough ball (don’t worry if it is a little sticky).
Place biscuits on a baking sheet and place in oven. Make sure they're touching. Bake until golden brown, approximately 10 to 15 minutes. Serves 6 to 8. Brush on the melted butter and enjoy!
NOTE: If you don't have a food processor, you can cut butter into flour in the mixing bowl using a grater, fork or a pastry cutter.