Preheat oven to 375 degrees.

Combine first 5 ingredients in a large bowl. Cut in butter with a pastry blender until mixture resembles coarse meal. Combine milk, 2 tablespoons orange rind, and 1/3 cup orange juice; add to flour mixture, stirring with a fork just until dry ingredients are moistened.

Drop dough by spoonfuls into 8 mounds on a lightly greased large baking sheet, leaving 1 inch of space between scones. Bake for 8 to 10 minutes or until golden. Transfer to a wire rack and let cool.

Combine remaining ½ teaspoon orange rind, remaining 2 tablespoons orange juice, and powdered sugar; drizzle over cooled scones.