In a large microwave-safe bowl, melt the butter, then set it aside to cool to room temperature. Ensure the butter is not hot to prevent greasy cookies.
Once butter is cooled, add to a large bowl. Add in both sugars, whisk until smooth. Mix in pumpkin and vanilla extract until combined.
In a separate bowl, combine flour, cream of tartar, salt, baking soda, cinnamon, nutmeg, cloves, allspice, and pumpkin pie spice. Whisk to combine.
Combine dry ingredients with wet, mixing until just combined. Avoid over-mixing. Cover and chill dough for 30 minutes.
Portion the dough into 45-gram, or roughly 2-tablespoon, balls. Combine granulated sugar and pumpkin pie spice for the spiced sugar coating. Roll the dough balls generously in the spiced sugar mixture. Add the shaped and rolled dough balls to a plate and place in the fridge for 30 minutes.
While the dough chills, preheat the oven to 350°F. Place 6 dough balls on a lined sheet with ample space between each. Bake for 9–12 minutes, aiming for slight underbaking. Let them sit on the tray for 5 minutes before moving to a cooling rack.
Remove and let stand on cookie sheet for 5 minutes before removing to a cooling rack.
Video
Notes
Note 1: Using the correct amount of flour is crucial. Too much can result in dry cookies, while too little can cause spreading. Consider switching to 'metric' on this recipe card and using a kitchen food scale. We're aiming for 395 grams of flour for this recipe.Storage: Enjoy cookies within 1-2 days; we like these even better day 2! Store extras in an airtight container at room temperature. If needed, form and roll any extra dough, then freeze it in an airtight container. You can bake the frozen dough balls without thawing.