Preheat oven to 425°F. Cover a baking sheet with parchment paper or silicone baking mat and set aside.
In a large mixing bowl combine the flour, baking powder, salt and sugar. Stir together.
Cut the butter into small cubes, and add to the dry ingredients. Cut into the flour using a pastry blender or food processor. Should have the texture of coarse meal, no large chunks of butter left.
Pour in the buttermilk and gently stir together. Will result in a shaggy dough.
Sprinkle a small amount of flour onto a clean work surface. Lay the dough on the floured surface and genly press together. Sprinkle small amounts of flour as needed on the dough if sticky.
Press dough together into a rectangular shape with the dough being 1/2 inch thick.
Cut using a 2-3 inch biscuit cutter. Press together remaining dough and cut additional biscuits until all dough has been cut.
Place the cut biscuits on the baking sheet close together, not quite touching. This helps the biscuits to rise.
Brush the tops of the biscuits with melted butter and sprinkle with coarse sugar.
Bake for 15-17 minutes until tops are golden and biscuits are baked through. Remove to wire rack and let the biscuits cool for 10 minutes before layering and serving.