Line a large baking sheet with parchment paper or a Silpat baking mat and set aside. In a medium bowl, whisk together the all-purpose flour, packed brown sugar, baking powder, kosher salt, ground cinnamon, ground nutmeg, ground ginger, and ground cloves until well combined.
In a separate medium bowl, combine the canned pumpkin puree, 1/3 cup heavy cream, large egg, and 1 teaspoon vanilla extract. Whisk until the mixture is smooth and homogenous. This will help ensure the liquid blends evenly into the dough.
Add the cold, cubed unsalted butter to the bowl of dry ingredients and quickly toss to coat. Using a pastry cutter or your fingers, cut or rub the butter into the flour mixture until you have a pebbly texture with pea-sized chunks of butter remaining. Pour the pumpkin mixture from Step 2 into the flour-butter mixture. Gently fold together with a spatula until just combined. Don't overmix—the dough will be wet and sticky. Knead the dough in the bowl just a few times until it comes together.
Turn the dough onto a lightly floured surface. Gently pat and shape it into a circle about 1 inch thick. Use a sharp knife to cut the dough into 8 even triangles. Arrange the pieces on your prepared baking sheet. Place the scones in the freezer for 15-20 minutes so the butter re-chills—this prevents the scones from spreading too much when baking. While chilling, preheat your oven to 400°F. I always find chilling the scones helps them bake up flakier and taller.
Remove the chilled scones from the freezer and brush the tops with the remaining 1 tablespoon heavy cream. Place the baking sheet on the middle rack of the preheated oven and bake for 15-22 minutes, until the tops and edges are golden brown and the centers are just set but slightly soft. Once baked, remove from the oven and let the scones cool on the sheet for 5 minutes before transferring to a wire rack to cool completely.
While the scones are cooling, prepare the cream cheese icing. In a medium bowl, whisk together the softened cream cheese, 2 tablespoons softened unsalted butter, powdered sugar, 1 to 2 tablespoons heavy cream or whole milk (adjust for desired consistency), and 1/2 teaspoon vanilla extract until smooth and spreadable. For a richer flavor, I prefer using heavy cream in the icing.
Once the scones have cooled completely, use a spoon to generously frost each one with the cream cheese icing from Step 6. Serve and enjoy—these are especially delicious with a hot cup of coffee or tea!