Preheat oven to 500ºF. Spray a 9 in springform or cake pan with some nonstick spray.
Add flour, baking powder, baking soda, sugar and salt to a bowl and mix the ingredients together evenly. Using a fork or pastry blender, cut in the butter until the pieces are no bigger than a small pea. Fold in the buttermilk until everything is just blended, and there are no streaks of flour remain. Do not overmix, the mixture should still be lumpy.
Line a plate or tray with some flour and using a 1/4 C measuring cup or 1/4 C ice cream/cookie scoop, scoop out balls of the dough onto the tray of flour. Flour your hands and roll each ball around in the flour to evenly coat them in a layer of flour. The dough is very wet and very sticky. Place the dough balls into the prepared pan. Place 9 balls around in a ring and 3 balls in the center of the pan. Brush the tops of the biscuits with melted butter.
Bake for 5 minutes at 500ºF (middle rack) and then lower the temperature to 450ºF and bake for another 15 minutes.