Whisk together the flour, cornstarch, cream of tartar, baking soda, salt, cinnamon, nutmeg & ground cloves.
In a separate large bowl beat together the butter and sugars until fluffy. Turn the mixer down to low then beat in the egg, vanilla and pumpkin.
Slowly add in the flour mixture. The dough will be very sticky.
Cover the bowl with clingfilm and refrigerate for at least 2 hours or up to 2 days.
When ready to bake, take the dough out of the fridge.
Preheat the oven to 350F degrees and line 2 cookie trays with parchment paper or silicone baking mats.
In a small bowl whisked together the sugar and cinnamon for the cinnamon sugar coating.
Form the dough into balls of about 1.5 tablespoons in size, then roll in the cinnamon sugar coating and flatten slightly
Place the cookies on the cookie sheets about 2 inches apart.
Bake for about 8-10 minutes until the tops look just set.