Take out butter to warm to room temperature and preheat oven to 450 degrees. In large bowl stir together the flour, baking powder, sugar, salt, and cream of tartar (all the dry ingredients). Using a pastry blender, cut in butter until mixture resembles course crumbs. Make a well in the center and add the buttermilk all at once. Stir until just mixed. Drop biscuits onto baking sheet. Bake in a 450 degree oven for 10 or 12 minutes or until golden brown.