In the bowl of a stand mixer fitted with the paddle attachment, cream the butter, sugars, and salt on medium-low speed until combined. Scrape the sides and bottom of the bowl to ensure there are no unmixed bits.

Add the egg yolks, vanilla, and pumpkin puree and mix to combine. Scrape the sides and bottom of the bowl.

Add the flour, pumpkin spice, and baking powder all at once to the mixer and mix on low speed until a dough starts to form. Scrape the sides and bottom of the bowl to ensure all the flour is combined into the dough.

Drop the dough onto a piece of very lightly dusted with flour piece of parchment paper. Use your hands to gently form a thick disc before dusting it lightly with more flour. Cover with another piece of parchment and roll to 1/4″.

Refrigerate the dough for 2 hours or overnight (and up to 3 days).

When ready to bake, preheat the oven to 375 F. 

Combine 50g (1/4 cup) granulated sugar with 1 Tbsp pumpkin spice or cinnamon. Cut cookies and coat each one in the spiced sugar mixture (top and bottom). Place the cookies on a parchment lined baking sheet and freeze for 5 minutes or refrigerate for 10-15. 

Bake the cookies for 8-10 minutes depending on the size. The size and thickness of the cookies will determine how long they bake, so pay attention to the surface of the cookies. The surface should be no longer shiny, and the tops should be evenly puffed. 

Cool the cookies on the cookie sheet for a few minutes before transferring them to a wire rack to cool completely before decorating. Moving them prematurely can result in broken cookies.