In a mixing bowl, combine the all-purpose flour, pumpkin pie spice, ground cinnamon, baking soda, cream of tartar, and salt. Whisk these together thoroughly.

In a large mixing bowl, cream together the softened unsalted butter, granulated sugar, and light brown sugar using an electric mixer until light and fluffy. Incorporate egg yolk, vanilla extract, and pumpkin puree; mix until smooth.

Gradually add the dry mixture to the wet mixture, mixing on low speed until barely combined, ensuring not to overmix.

Transfer the cookie dough into an airtight container or cover with plastic wrap. Chill for at least 30 minutes.

Preheat your oven to 350°F (177°C) and line two baking sheets with parchment paper.

Scoop dough onto baking sheets, leaving 2 inches of space between each cookie. Aim for about 12 cookies per sheet.

In a small bowl, mix granulated sugar and ground cinnamon for coating. Roll each dough ball in the mixture until fully coated.

Bake for 10-13 minutes until edges are set; allow to cool on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.