1. Preheat oven to 450°.
2. Weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 4 ingredients (through salt) in a bowl. Use fingertips to incorporate butter pieces into flour mixture until they are thoroughly distributed; pieces of butter about the size of peas should still be visible. Add buttermilk, cranberries, and orange rind, stirring just until moist.
3. Turn dough out onto a lightly floured surface; knead lightly 4 times with floured hands. Pat dough into an 8-inch circle on a baking sheet coated with cooking spray. Cut dough into 8 wedges. Place wedges 2 inches apart on an ungreased baking sheet. Brush wedges with 1 tablespoon buttermilk and sprinkle with 1 tablespoon sugar.
4. Bake at 450° for 11 minutes, or until golden.