1. Preheat oven to 400 degrees. 2. Combine flour, baking powder, salt and baking soda in food processor. Pulse once or twice to combine. Add butter. Pulse 10 to 12 times or until mixture resembles fresh bread crumbs. (You can use pastry blender to cut butter into flour if you don't have a food processor.) 3. Transfer mixture to large bowl. Add 1 cup buttermilk, stirring quickly to combine. If mixture is too dry, add more buttermilk, 1 tablespoon at a time, until dough holds together and is slightly stringy and crumbly. Turn out onto lightly floured surface. Knead 6 to 7 times (do not knead more than that or scones will become tough). 4. Divide dough in half. With floured hands, press each half into 9x4-inch rectangle. With short side facing you, fold into thirds like a business letter. Press each portion into 6 to 7-inch circle; place on ungreased baking sheet. Cut each circle into 6 equal wedges; pull wedges slightly apart. Brush tops with remaining buttermilk. Let stand 10 minutes. 5. Bake in 400 degree oven for 20 minutes, or until tops are lightly browned. Remove and serve warm.

Ham and Sage Scones: Add 4 ounces cubed boiled ham and 1 teaspoon dried sage with butter. Pulse 10 to 12 times until ham pieces are no larger than grains of rice. Instead of pressing dough into circles, press each half into 7 1/2-inch square. Cut each into 8 squares.

Cheddar Cheese Scones: Add 4 ounces cubed Cheddar and 1/4 to 1/2 teaspoon cayenne pepper along with butter. Process 10 to 12 times until cheese pieces are no larger than dried peas. After brushing tops with buttermilk, sprinkle with sesame seeds, using about 2 teaspoons total.

Rosemary and Black Olive Scones: After dividing dough in half, scatter 1/2 teaspoon crumbled dried rosemary and 1/4 cup chopped kalamata olives (about 10 olives) over each batch of dough before it is folded into thirds.