1Preheat oven to 425 degrees. In a small bowl, combine 1/3 cup sugar with about 1/2 of the grated orange zest. Rub together with your fingers until combined and fragrant.
2In large bowl combine flour, orange sugar, salt, baking soda and powder. Using your fingers, a fork or a pastry blender, cut in butter until it forms coarse crumbs. Stir in buttermilk and vanilla, and add half of the remaining orange zest. Add the juice from 1/2 of one blood orange. Stir with a spoon until a dough forms, using your hands to bring it together. Turn onto a lightly floured surface and knead gently.
3Divide in half and pat into 7 inch round circles. Combine the remaining sugar and orange zest. Brush each scone with melted butter and sprinkle with orange sugar. Cut into 6 or 8 wedges, or use a biscuit cutter to make rounds.
4Bake for 12-14 minutes (wedges) or 9-11 minutes (rounds). Top with blood orange glaze.