In a medium bowl, whisk together flour, cornstarch, cream of tartar, baking soda, and salt. Add cinnamon, nutmeg, and cloves. Set aside.

In a large mixing bowl, beat together butter, brown sugar, and white sugar until fluffy, about 2-3 minutes. Add egg, vanilla extract, and pumpkin puree. Mix until smooth.

Gradually add the dry mixture to the wet ingredients while mixing on low speed until a sticky dough forms.

Refrigerate the dough for at least 30 minutes.

Preheat your oven to 350°F (175°C) and line baking sheets with parchment.

Scoop tablespoon-sized portions of dough, roll into balls, and optionally roll in cinnamon sugar. Place on prepared trays.

Bake for 8-10 minutes until set but slightly underbaked in the center.

Cool on baking sheets for 5 minutes before transferring to a wire rack.