1 tablespoon demerara sugar for sprinkling (optional)
Instructions
Adjust oven rack to lower-middle position and heat oven to 400 degrees. Mix flour, sugar, pumpkin pie spice, baking powder, salt, baking soda in a medium bowl. Grate ⅓ of the butter into the flour mixture on the large holes of a box grater; toss. Repeating grating and tossing twice more. Using fingertips, work butter into flour a bit more.
Mix pumpkin puree, sour cream, and egg yolk with a fork until smooth. Using same fork, stir into dry ingredients until large dough clumps form. Use hands to press dough against the bowl into a ball. (There may not seem like enough liquid at first, but as you press, the dough will come together. If necessary, flick a little water into bowl bottom to get the last bits to adhere.)
Place on a lightly floured work surface and pat into a 7½-inch circle, about ¾-inch thick. Brush with egg white, sprinkle on nuts, pressing to adhere, and sprinkle with optional demerara sugar. Use a sharp knife to cut into 8 triangles; place on a cookie sheet (preferably silpat- or parchment-lined), about 1 inch apart. Bake until golden, about 15 to 17 minutes. Cool for 5 minutes and serveāhot, warm, or at room temperature.
Notes
If you don't have demerara sugar, just sprinkle the scone tops with a little granulated sugar.
Recipe by Three Many Cooks at https://threemanycooks.com/recipes/sweet-treats/pumpkin-walnut-scones/