2½cups (300g) all-purpose flour (measured correctly — spoon and level!)
1tbspcornstarch
1tspcream of tartar
1tspbaking soda
¼tspbaking powder
½tsp ground cinnamon
½tspeach: ground nutmeg, ground ginger, salt
¼tspeach: ground cloves, ground allspice
Creaming Ingredients
¾cupgranulated sugar
⅔cuppacked light brown sugar
12tbsp(1½ sticks) unsalted butter, room temperature
1large egg yolk (just the yolk!)
½cuppure pumpkin puree (Libby’s brand preferred)
1½tspvanilla extract
Rolling Mixture
Rolling Mixture¼cupgranulated sugar
1tspground cinnamon
Instructions
Mix the Dry IngredientsIn a medium bowl, whisk together the flour, cornstarch, cream of tartar, baking soda, baking powder, and all the spices. Set aside.
Cream the Butter and SugarsIn a stand mixer fitted with the paddle attachment, beat the butter, granulated sugar, and brown sugar on medium speed until creamy and fluffy — about 2 minutes.
Add the Wet IngredientsMix in the egg yolk, then the pumpkin puree and vanilla. Scrape down the sides to make sure everything’s evenly combined.
CombineReduce the mixer to low and slowly add the dry ingredients. Mix until just combined — don’t overbeat! Give the dough one final stir by hand.
Chill the DoughCover the bowl and refrigerate for at least 1 hour, preferably up to 3. Chilling prevents spreading and gives you thicker, chewier cookies.
Shape and RollPreheat the oven to 350°F (175°C). Line baking sheets with parchment or silicone mats.Scoop about 2 tablespoons of dough per cookie, roll into balls, then coat each in the cinnamon-sugar mixture. For extra-thick cookies, make the dough balls slightly taller than wide.
BakePlace cookies 2 inches apart and bake for 10–13 minutes, until the tops are set and starting to crack. They should look slightly underbaked — they’ll continue cooking on the sheet.
CoolLet cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack.(Pro tip: If they’re not spreading enough by minute 9, remove the tray and tap it gently on the counter a few times before finishing in the oven.)