To make the dough: In a medium bowl, combine the sugar, butter, spice, vanilla, and salt. Set aside.

Place the pumpkin in a small saucepan and cook over medium heat, stirring frequently with a heatproof spatula, until the pumpkin is darker in color and dry enough that it starts to stick to the sides of the pan, 7 to 10 minutes. Stir with more frequency toward the end of the cooking time and lower the heat as needed to prevent scorching. At the end of cooking, you should be left with about 1/2 cup (120g). If you have a little more or a little less, that’s OK; proceed with the recipe. If you have significantly more, return the mixture to the pan and continue to cook.

Immediately transfer the reduced pumpkin to the bowl with the sugar-butter mixture and stir together with a flexible spatula until the butter is completely melted and the dough is smooth. If necessary, use the spatula to smear the butter chunks into streaks to encourage them to melt.

Add the flour, baking powder, and baking soda and continue to stir with a spatula until fully incorporated and no dry spots remain.

Cover the bowl and refrigerate for at least 1 hour and up to 24. The dough will become firm as it chills.

When you're ready to bake, preheat the oven to 350°F with racks in the upper and lower thirds. Line two baking sheets with parchment.

Bake for 15 to 18 minutes, rotating the pans halfway through baking. The Pumpkin Crinkle Cookies will have puffed; the centers should be set but not firm.

Remove from the oven and allow the cookies to cool completely on the baking sheet. The centers will slightly collapse as they cool; serve at room temperature.

Storage information: Store leftover Pumpkin Crinkle Cookies in an airtight container at room temperature for several days; freezing is not recommended.