Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.

In a large mixing bowl, combine freshly milled soft white wheat flour, sugar, baking powder, salt, and pumpkin spice. Whisk until evenly mixed.

Grate very cold butter into the flour mixture and rub gently until it resembles coarse crumbs.

In a separate bowl, whisk pumpkin purée, half and half, and the egg until smooth.

Pour the wet mixture into the dry ingredients and fold together gently until just combined.

Turn the dough out onto a floured surface and shape into a 1-inch thick circle, cutting into 8 equal triangles.

Bake for approximately 15 minutes or until golden brown and fragrant.

Cool the scones on a wire rack for at least 15-20 minutes before glazing.

Whisk together powdered sugar, half and half, and arrowroot powder until smooth for the glaze.

Drizzle the glaze over the cooled scones and let set before serving.