Preheat oven; whisk dry ingredients: Preheat oven to 425°F. In a bowl, whisk together flour, 5 tablespoons sugar, baking powder, and salt.
Cut in butter; stir in half-and-half and add cranberries: Cut in butter with a pastry blender or two knives until mixture resembles coarse crumbs. Stir in ⅔ cup half-and-half until just moistened. Gently fold in cranberries.
Form scones: On a lightly floured surface, knead dough gently, 5 to 10 times. Pat into a 1-inch-thick round. Cut into 8 wedges; place on a baking sheet, 2 inches apart. Brush tops with remaining tablespoon half-and-half; sprinkle with remaining tablespoon sugar.
Bake: Bake until golden brown, 12 to 15 minutes. Let cool on a wire rack.
