01 -  Preheat oven to 400°F. Line a large baking sheet with parchment paper. 
 02 -  Whisk together flour, light brown sugar, baking powder, baking soda, salt, cinnamon, ginger, and nutmeg in a large bowl. 
 03 -  Add cold, cubed butter to the dry mixture and cut it in using a pastry blender or fingertips until it resembles coarse crumbs. 
 04 -  Whisk together pumpkin puree, buttermilk, egg, and vanilla extract in a separate bowl until smooth. 
 05 -  Gently stir wet mixture into dry ingredients just until combined. Avoid overmixing. 
 06 -  Fold mini chocolate chips and chopped walnuts or pecans (if using) into the dough to distribute evenly. 
 07 -  Turn the dough onto a lightly floured surface and pat into a 1-inch thick disk. Cut into 8 equal wedges. 
 08 -  Place scones on prepared baking sheet with space between each. Brush tops lightly with buttermilk, then sprinkle with coarse sugar and extra mini chocolate chips. 
 09 -  Bake for 18 to 22 minutes, until golden brown and a toothpick inserted into the center comes out clean. 
 10 -  Allow scones to cool slightly before serving warm or at room temperature.