How to Make It
Preheat oven to 400°. Combine first 5 ingredients; cut in butter with pastry blender until mixture resembles a coarse meal.
Whisk together the buttermilk, egg, and vanilla. Add to dry ingredients with cranberries; stir just until moist.
On lightly floured surface, knead dough with floured hands 5 or 6 times; pat into 7-inch round. Cut into 6 wedges; transfer wedges to parchment-lined baking sheet.
Brush tops with egg white, and sprinkle with coarse sugar. Bake 15 minutes or until golden. Let cool on wire rack 10 minutes before serving.