Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a large mixing bowl, cream together the softened butter, egg yolk, vanilla extract, brown sugar, and granulated sugar until the mixture is light and fluffy.
Mix in the pumpkin puree and cinnamon until well combined. The pumpkin adds moisture and that delicious fall flavor.
In a separate bowl, whisk together the flour, pumpkin pie spice, baking soda, and salt.
Gradually add the dry ingredient mixture to the wet ingredients, mixing until just combined. Don't overmix; just mix until no streaks of flour remain.
Gently fold in the white chocolate chips. They'll add a delightful sweetness and creaminess to each bite.
Using a cookie scoop or your hands, form cookie dough balls about 1-2 tablespoons in size. Place them on the prepared baking sheet with some space in between.
Bake in the preheated oven for about 10-12 minutes, or until the edges turn golden brown. The centers will seem slightly undercooked, but they'll firm up as they cool, giving you that perfect soft and chewy texture.
