Preheat oven to 425°F. Line rimmed baking sheet with parchment paper. In large bowl, whisk together millet flour, sorghum flour, white rice flour, granulated sugar, baking powder, salt, xanthan gum, cinnamon, nutmeg, cloves, and ginger. Using your hands or a pastry cutter, cut butter into dry ingredients until no large pieces of butter remain. Mixture should resemble a coarse cornmeal.

In small bowl, whisk together pumpkin puree, half and half, and egg. Add to dry ingredients. Stir until a wet dough forms. Turn dough out onto prepared making sheet. Spray top of dough lightly with nonstick cooking spray. Using your hands, pat the dough into a circle about 1/2-inch thick. Use a sharp knife and cut the dough into 8 or 12 wedges.

Bake until golden brown, about 18 minutes. Remove pan from oven. Quickly cut wedges again. Sometimes they stick together during baking. Allow scones to cool on the pan.

Prepare the vanilla glaze Stir together powdered sugar, half and half, and vanilla together in a small bowl. The glaze should flow easily from a spoon. If it doesn't add an additional teaspoon of half and half to the glaze. Place a wire cooling rack over a piece of parchment paper. Spoon the glaze evenly over the cooled scones. Allow to glaze to harden. Prepare the pumpkin glaze. In small bowl, stir together powdered sugar, pumpkin puree, half and half, cinnamon, nutmeg, ginger, and cloves. Glaze should be thick. Transfer glaze to a piping bag. Drizzle glaze over each scone. If you don't have a piping bag, place glaze into a plastic sandwich bag and snip one of the corners to make a bag or thin glaze with half and half and drizzle from a fork onto scones.