Preheat oven to 350 degrees. Line cookie sheets with parchment paper or silicone mats.
Add flour and pumpkin pie spice to a medium bowl and whisk until well combined, set aside.
Blot the water out of the pumpkin. Do this by laying 2-3 layers of paper towels down, spread the pumpkin thinly on the paper towel, and press down with another paper towel to absorb water. Continue this process until the pumpkin is less shiny and more of a matte texture (see post above for more details on this process).
In a large bowl, beat the butter, granulated sugar, and brown sugar with an electric mixer until well combined and one solid color.
Add the egg yolk and scrape the blotted pumpkin from the paper towel with a spatula into the mixing bowl. Beat on medium speed until combined. The dough will start to look more orange.
Add the dry ingredients in three sections, beating with the electric mixer on low-medium speed until combined between each addition. Scrape the bowl with a spatula to make sure all of the dry ingredients have been mixed in.
Using a medium cookie scoop, form balls and roll them between your palms to make a smooth cookie dough ball. The ideal size is 15-17g if you have a food scale.
Using your thumb or the round base of a teaspoon, press down on each ball to make a hole in the center.
Bake at 350 degrees for 10 minutes or until the bottom edge of the cookie is slightly brown. After baking, the cookie will slightly rise and make the hole less visible. Use a base of a teaspoon or something with a round shape and repress each hole. Let the cookies cool for 5-10 minutes on the cookie sheet before removing them and let completely cool on a wire cooling rack.