Cream the Butter: In a large mixing bowl, beat the room temperature butter, granulated sugar, and brown sugar with an electric hand mixer for 2 to 3 minutes, until creamy and fluffy.
Add the Flavor: Add the egg yolks, pumpkin puree, cinnamon, salt, nutmeg, ginger, and vanilla extract, and mix well.
Dry Ingredients: Add the flour and baking soda and mix just until combined. Don't overmix, or the cookies can turn cakey.
Chill: Cover the bowl with plastic wrap and refrigerate the dough for at least 1 hour, or overnight for the best flavor.
Shape and bake
Cinnamon Sugar: In a small bowl, mix the cinnamon, brown sugar, and granulated sugar.
Scoop: Preheat your oven to 180°C (350°F) and line a baking sheet with parchment paper. Scoop the dough with a cookie scoop or a tablespoon and roll it into balls with clean hands.
Roll and Bake: Roll each dough ball in the cinnamon sugar and place it on the baking sheet, leaving space between each cookie. Bake for 12 to 14 minutes, until the edges are set and the centers still look slightly soft.
Cool: Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.
Notes
Chill the Dough: Refrigerate the dough for at least 1 hour, or overnight, so the cookies spread less and stay thick and chewy.
Pumpkin Puree: Use plain canned or homemade pumpkin puree, not pumpkin pie filling, which already has sugar and spices.
Egg Yolks Only: Use just the yolks. They add richness and keep the cookies chewy instead of cakey.
Room Temperature Butter: The butter should be soft to the touch but not melted so it creams properly with the sugar.
Don’t Overmix: Mix the flour in just until combined to keep the cookies chewy.
Measure Flour Correctly: Spoon the flour into your measuring cup and level it off, or use a kitchen scale. Too much flour makes the cookies dry.
Pull Them Out Early: Bake until the edges are set and the centers still look slightly soft. They finish setting as they cool.
Storage: Keep the cookies in an airtight container at room temperature for up to 4 days, or freeze for up to 3 months.