1. Heat oven to 375 degrees. Grease cookie sheet.
2. Cut butter into flour, sugar, baking soda, baking powder and salt in large bowl, using pastry blender until mixture resembles fine crumbs. Stir in just enough buttermilk so dough leaves side of bowl.
3. Turn dough onto lightly floured surface. Knead 1 to 2 minutes or until smooth. Shape into round loaf, about 6 1/2 inches in diameter. Place on cookie sheet. Cut an X shape about 1/2 inch deep through loaf with floured knife.
4. Bake 35 to 45 minutes or until golden brown. Brush with butter, softened, if desired.