Preheat the oven to 350 degrees F. In a medium bowl combine flour, pumpkin pie spice, cinnamon, baking soda, cream of tartar and salt. Set aside.
In a large mixing bowl using an electric mixer, cream together the butter, coconut sugar, and brown sugar until well combined. Mix in the egg yolk and vanilla extract, then mix the pumpkin puree, stopping to scrap down the sides of the bowl as needed.
Add the dry ingredients to the wet ingredients and mix until just combined.
Refrigerate for 30 minutes.
Line a baking sheet with parchment paper or a silicon baking mat.
Mix the pumpkin pie spice and sugar together in a small bowl
Remove the cookie dough from the fridge and portion out using a cookie scoop. Roll each cookie in the pumpkin spice sugar mixture and place on a baking sheet. They won't spread a ton so you don't have to put them super far away from each other.
Bake for about 12 minutes until the cookies are set. Let cool. Repeat with any leftover dough. Store cookies in an airtight container on the fridge for up to a week.