How to Make It
Preheat the oven to 425° and line a baking sheet with parchment paper. In a bowl, whisk the flour, oats, baking powder, salt and 3 tablespoons of the sugar. Using a pastry blender or 2 knives, cut in the butter until the mixture resembles coarse meal. Mix in the cranberries and orange zest. Stir in the 1/2 cup of buttermilk until a stiff dough forms; knead until it just comes together.
On a floured surface, pat the dough into a 3/4-inch-thick round and cut into 8 wedges. Brush with buttermilk. Sprinkle the remaining sugar on top. Transfer to the baking sheet and bake in the center of the oven for 17 minutes, until lightly browned. Transfer the scones to a rack and let cool slightly. Serve warm or at room temperature.