In a large bowl, combine the flour, 1/3 cup sugar, baking powder, baking soda and salt. Cut in butter until mixture resembles coarse crumbs. Stir in buttermilk just until moistened. Fold in chips.
Turn onto a lightly floured surface; knead gently 10-12 times or until dough is no longer sticky. Divide in half; gently pat or roll each portion into a 7-in. circle. Brush with butter and sprinkle with remaining sugar.
Cut each circle into six wedges. Separate wedges and place on an ungreased baking sheet. Bake at 425° for 10-13 minutes or until lightly browned. Serve warm.