Whisk together the all-purpose flour, cornstarch, cream of tartar, baking soda, salt, ground cinnamon, ground nutmeg, and ground cloves until well combined. Set aside.

Use an electric mixer to beat together the unsalted butter, packed light brown sugar, and white sugar until light and fluffy. Then add the egg, vanilla extract, and canned pumpkin, mixing until incorporated.

Gradually add the dry mixture into the wet mixture, continuing to mix until a very sticky dough forms. Cover and refrigerate for at least 2 hours.

Preheat your oven to 350°F (175°C) and line baking trays. Whisk together white sugar and ground cinnamon for the coating.

Form the chilled dough into balls about 1.5 tablespoons in size. Roll each ball in the cinnamon sugar coating and flatten slightly before arranging on baking trays.

Bake in the preheated oven for 8-10 minutes until the tops are just set. Allow to cool on the trays before transferring to a wire rack.