Preheat Your Oven. Set it to 400°F and line a baking sheet with parchment paper.
Mix Dry Ingredients. In a large bowl, whisk together flour, sugar, baking powder, salt, and spices.
Cut in the Butter. Using a pastry cutter or your fingers, cut the cold butter into the flour mixture until it resembles coarse crumbs.
Combine Wet Ingredients. In a separate bowl, whisk together pumpkin puree, heavy cream, and vanilla extract.
Bring It All Together. Pour the wet ingredients into the dry ingredients and gently mix until just combined. Add in chopped walnuts if using. Do not overmix.
Shape and Cut the Dough. Turn the dough onto a floured surface, shape it into a circle about 1 inch thick, and cut it into 8 wedges.
Bake. Place the wedges on the prepared baking sheet and bake for 15-20 minutes or until golden brown.