In large bowl combine the flour, orange sugar, salt, cinnamon, baking soda and powder. Using your fingers, a fork or a pastry blender, cut in butter until it forms coarse crumbs. Stir in the buttermilk and vanilla, and add the remaining orange zest. Add the juice from 1/2 of one of the zested oranges. Stir with a spoon until a dough forms, using your hands to bring it together. Turn onto a lightly floured surface and knead gently.