Make the dough: Whisk the dry ingredients together in a large mixing bowl.
300 grams all-purpose flour, 20 grams baking powder, ¼ teaspoon baking soda, 1 teaspoon cinnamon, ⅛ teaspoon nutmeg, 3 whole cloves, ½ teaspoon ground ginger, 4 whole all spice
Rub the butter into the dough until coarse crumbs resembling wet sand forms. Transfer the flour mixture to the refrigerator or freezer. This helps keep the butter cool.
113 grams unsalted butter
Whisk the wet ingredients and sugar together until no traces of egg or discard remain. Set aside.
1 large egg, 100 grams brown sugar, 113 grams sourdough discard, 56 grams buttermilk, 113 grams pumpkin puree
Make a well in the center of the flour mixture. Pour half of the wet ingredients into the well. Gently fold the wet ingredients into the dry ingredients until the flour is hydrated. Drizzle the remaining wet ingredients into the outside edge of the bowl where most of the dry flour remains. Continue mixing the ingredients until most of the flour is hydrated.
Turn the dough out onto the center of a large piece of parchment paper. Use the edges of the parchment to fold the dough on itself. This helps keep the butter cool and prevents you from overworking the dough. Give the parchment a quarter turn and fold the dough again. Repeat 6 to 8 times or until the dough comes together and only a few specks of dry flour remain.
Transfer the dough with the parchment paper to an 8-inch cake pan. Flatten the dough until it fills the pan.
Chill the dough: Fold the parchment over the dough. Transfer the pan to the refrigerator and let the dough chill for at least 1 hour.
Prep: Preheat the oven to 420 F and line a large baking sheet (18 by 13 inches) with parchment paper. Whisk eggwash ingredients and set aside.
14 grams buttermilk, 1 large egg
Shape the scones: Divide the dough into 8 even portions. Arrange the scones on the prepared baking sheet at least 2 inches apart. Brush egg wash on the top of the dough. Don’t brush the sides.
Bake: Bake the scones at 420 F for 10 minutes. Turn the oven temperature down to 350 F, rotate the pan and continue another 10 to 15 minutes until the tops are golden brown.
Transfer the baked scones to a wire rack and cool for 10 minutes.
Make the glaze: Whisk the glaze ingredients together until smooth.
14 grams pumpkin puree, 1 teaspoon cinnamon, 14 grams buttermilk, 90 grams powdered sugar
Serve: Drizzle or spoon the glaze over the cooled scones. These scones are best enjoyed the day they are baked.
Store: Store any leftovers in a brown paper bag at room temperature for up to 2 days.