Preheat oven to 500°F.  In a large bowl whisk together flour, baking powder, and salt.  Cut the cold butter up into 1/2 inch pieces. Add the butter, coating in flour and working quickly, rub the butter between your fingers, breaking it into smaller pieces.  Do this with about half of the pieces and leave the remaining.

Make a well in the center of the flour mixture and add buttermilk.  Mix quickly until just blended and forms a sticky dough.  If it is too dry, add more buttermilk one tablespoon at a time.

Turn dough onto a heavily floured surface.  Using floured hands, knead 8 to 10 times until a cohesive ball forms.  Flatten the dough to an even thickness.  With a floured rolling pin, roll the dough to 3/4 inch thickness.

Using a fork dipped in flour, pierce dough completely through at 1/2 inch intervals.  Flour a 2 1/2 - 3 inch biscuit cutter.  Stamp out rounds and arrange on parchment lined baking sheet.  Makes about 16 biscuits.  Place rack in upper third of the oven and bake for 8-12 minutes until golden brown.  Remove and brush with melted butter.  Serve hot.

*homemade baking powder: 1 teaspoon baking soda and 2 teaspoons of cream of tartar.