Preheat the oven to 425 degrees F (220 degrees C). Line a heavy baking sheet with parchment paper.

Whisk flour, sugar, baking powder, and salt together in a medium bowl. Stir in grated orange zest. Cut in cold butter with 2 knives or a pastry blender until butter is the size of small peas. Mix in cranberries and walnuts.

Mix 1/2 cup cream and egg in a small bowl until well combined. Add to the flour mixture and stir with a spoon or by hand until just combined and dough comes together. Divide dough in half and form into two 3/4-inch thick circles. Cut each circle in half, and cut each half into 3 triangular-shaped scones. Place scones on the prepared baking sheet and brush with remaining 2 tablespoons heavy cream.

Bake in the preheated oven until the edges begin to brown slightly, 13 to 15 minutes.

Meanwhile, mix confectioners' sugar, orange juice, and orange extract together in a small bowl until completely combined. Drizzle glaze over scones and serve warm.