Heat oven to 500°F.
In a large bowl mix together flour, baking powder, and kosher salt.
Add chilled butter, coating in flour.
Working quickly, rub butter between fingertips until roughly half the butter is coarsely blended and half remains in large pieces, about 3/4”.
Make a well in center of flour mixture.
Add buttermilk all at once.
With a large spoon stir mixture quickly, just until it is blended and begins to mass and form a sticky dough. (if dough appears dry, Add 1 to 2 Tbsp additional buttermilk)
Immediately turn dough onto generously floured surface.
Using floured hands, Knead briskly 8-10 times until cohesive ball or dough forms.
Gently flatten dough with hands to even thickness.
Using a floured rolling pin, lightly roll dough dough to 3/4” thickness.
Using a dinner fork dipped in flour, pierce dough completely through at 1/2” intervals.
Flour a 2.5 or 3” biscuit cutter.
Stamp out rounds and arrange on heavy parchment-lined baking sheet.
Add dough pieces, as-is, to baking sheet.
Place on rack in upper third of oven.
Bake at 350°F for 8-12 minutes until crusty and golden brown.
Remove from oven.
Brush with melted butter.
Serve hot.