Preheat oven to 400°F. Line a baking sheet with parchment paper.
Whisk together flour, brown sugar, baking powder, salt, cinnamon, ginger, nutmeg, and cloves.
Grate the cold butter into the flour mixture and toss gently to coat.
In a separate bowl, whisk together sourdough discard, pumpkin puree, egg, and vanilla.
Add the wet ingredients to the dry ingredients. Fold gently until a shaggy dough forms. If necessary, add milk or cream 1 tablespoon at a time.
Turn the dough onto a lightly floured surface. Gently press together and fold the dough over itself 2–3 times.
Pat into a 7–8-inch circle approximately 1 inch thick.
Cut into 8 wedges and arrange on the prepared baking sheet.
Chill for 15–20 minutes.
Brush the tops lightly with cream or milk and sprinkle with coarse sugar, if desired.
Bake for 18–22 minutes, until risen and lightly golden.
Cool for about 10 minutes before serving or glazing.