Preheat an oven to 220C (450F). Lightly grease a baking sheet with butter or use a silpat liner.
In a food processor, pulse the flour and butter until the mixture resembles coarse meal. Transfer to a bowl.
Alternatively, in a bowl, stir together the dry ingredients. Then, using a pastry blender, cut in the butter until the mixture resembles coarse meal.
Make a well in the center of the flour mixture and pour in the buttermilk. Using a fork, mix together until a soft elastic dough forms.
Turn out the dough onto a lightly floured work surface and knead 5 or 6 times until the dough is smooth. Roll out about 3/4 inch thick. Using a scallop-edged cookie cutter 3 inches in diameter, cut out rounds. Transfer to the prepared baking sheet.
Bake the scones until they rise and are golden brown on top, about 15 minutes. Serve hot.