Preheat the oven to 350° F. Line the cookie sheets with parchment paper or spray them with non-stick spray, then set them aside.
Combine the softened unsalted butter, sugar, and brown sugar in a stand mixer bowl. Cream the ingredients until smooth
1 cup unsalted butter, ½ cup sugar, ¾ cup brown sugar
Add the pumpkin puree, large egg yolks, vanilla, pumpkin pie spice, salt, cream of tartar, and baking soda to the large mixing bowl. Mix them well.
½ cup pumpkin puree, 2 egg yolks, 2 tsp vanilla extract, 1 ½ tsp pumpkin pie spice, 1 ½ tsp cream of tartar, 1 tsp salt, 1 tsp baking soda
Mix in the flour with the wet ingredients. Make sure to scrape the sides of the bowl before mixing again. You’ll end up with a sticky-looking dough.
2 cup flour
In a separate small bowl, mix the remaining dry ingredients (sugar and cinnamon) for rolling.
⅓ cup sugar for rolling, 1 tsp cinnamon for rolling
Scoop out golf-ball-sized doughs from the bowl, then roll them in the cinnamon/sugar mixture.
Place the dough on the cookie sheet, making sure to leave plenty of space between them so they can spread.
Bake in the oven for about 10-12 minutes, or until the edges have turned slightly brown. The center should still be puffy, but that will settle once the cookies have cooled.
Allow the pumpkin snickerdoodles to cool on the baking sheet for about 5 minutes, then transfer to a wire rack so they’ll finish cooling.
Serve and enjoy!