Preheat oven to 425 degrees.
In a large bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, cardamom, nutmeg, ginger, cloves, and brown sugar. Shred the butter on a coarse cheese grater and mix in.
In a separate bowl, whisk together the pumpkin puree, buttermilk, egg, vanilla extract and honey. Add to the flour mixture and mix with a wooden spoon to incorporate. You may have to gently knead the dough to make it come together.
Turn the dough over on a lightly floured work surface. Roll the dough out into an 8-inch disk and cut into 8 equal wedges.
Transfer the wedges onto a parchment paper-lined baking sheet. Brush tops with one tablespoon of heavy cream, then bake for 13 - 15 minutes or until tops are golden brown and a toothpick inserted into the center comes out clean.
Transfer the scones to a cooling rack and chill for 10 minutes before glazing.
In a small bowl, whisk together powdered sugar and heavy cream, then use the mixture to glaze the scones. Let the glaze set.
In the same bowl, whisk together powdered sugar, pumpkin puree, cinnamon, nutmeg, ginger and the heavy cream. Drizzle the mixture over the scones. Let set at room temperature then serve.