Pulse the dry ingredients together in a food processor until they are mixed; this should be about 6 one-second pulses. Cut the butter into cubes, and use 8-10 more pulses to mix the butter into the dry ingredients. Move everything to a bowl and mix in the buttermilk.
Scoop out ¼ cup of dough at a time, drop the scoop onto the floured cutting board, and roll the scoop into a ball (using floured hands). Arrange the balls of dough in the baking pan - you should end up with 12 of them. Optionally, brush with melted butter. Bake for 5 minutes at 500 degrees, then 15 minutes at 450 degrees. Cool in the pan for two minutes, then dump them out and let cool for 5 minutes.