Preheat oven to 375°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 4 ingredients in a bowl. Cut in butter with pastry blender or 2 knives until mixture resembles coarse meal. Stir in cranberries and rind. Add buttermilk and egg, stirring just until moist.
Turn dough out onto a lightly floured surface, and knead 15 times or until smooth.
Transfer dough to a baking sheet coated with cooking spray; pat into a 7-inch circle. Cut into 10 wedges, cutting to, but not through, bottom of dough. (Do not separate wedges.)
Bake at 375° for 20 to 22 minutes or until golden. Transfer scones to a wire rack; sift powdered sugar over top, and serve warm.