Place your butter in the freezer for about 20-30 minutes while your sweet potato cools. Line a baking sheet with parchment.
In a large bowl, add flour, dark brown sugar, salt, baking powder, baking soda, and cinnamon. Whisk together.
Take your butter from the freezer and grate into your flour mixture. Halfway through, stop and fluff the butter into the flour using a fork. Grate remaining butter in and repeat.
Create a well in the middle of your ingredients and add pumpkin puree, heavy cream, beaten egg, and vanilla.
Using a fork, bring the dry ingredients into the wet and mix gently until a rough dough comes together. When the dough is crumbly and rough, add your chocolate chips and mix in.
Gather the dough together using your hands into a disc like shape in the bowl. Fold the dough over onto itself, press back out and repeat 2 more times.
Place the dough onto your lined baking sheet and press out into a square or circle that is about 1½ inches thick.
Using a knife or bench scraper, cut into 8-9 pieces (depending on shape). When you cut, do not use a sawing motion but cut straight down.
Pull the scones slightly apart, and place into freezer to chill for about 20 minutes.
Preheat your oven to 425°F.
When oven is ready your scones should feel quite cold and a little more firm but not frozen, remove them from the freezer and brush the tops with heavy cream. If you do not plan to glaze them, I'd recommend sprinkling them with some turbinado sugar.
Bake the scones on the center rack of your oven for about 22-25 minutes. The tops should be lightly golden. Remove from oven and transfer to a cooling rack.
While scones cool, prepare the glaze. In a medium-small bowl, add your softened cream cheese, cocoa powder, powdered sugar, salt and milk. Whisk until smooth.
When scones have cooled, spoon or drizzle glaze on top. Store scones in an airtight container for 2-3 days, but they are best right after baking. Enjoy!
Notes
** If you do not have pumpkin pie spice, substitute 3/4 tsp cinnamon, 1/2 tsp nutmeg, 1/2 tsp ginger, 1/4 tsp allspice, 1/4 tsp clove