Pre-heat oven to 350 degrees. Place parchment paper on 2-3 cookie sheets depending on size.
In a large bowl, using a sifter, sift the AP Flour, Pumpkin Pie Spice, Baking Soda, Cream of Tartar and Salt together.
In a large bowl with an electric stand mixer or handheld mixer, add slightly melted butter, white sugar and brown sugar. Mix on low speed until well combined. Add the egg, vanilla and mix. Lastly, add the pumpkin puree and mix.
Slowly add the dry ingredients to the wet ingredients in the stand mixer on low speed. I like to use a large spoon and add a few scoops at a time until well mixed. This might take a few minutes.
Roll the cookie dough into about 20 cookie balls, about 2 tablespoons per portion. If the dough is sticky, place the dough into the fridge for a few minutes to chill. Then try again.
Place cookie balls on the prepared cookie sheets. Bake at 350 degrees for about 12-14 minutes or until edges start to crisp and the centers look cooked through and not shiny.
After a few minutes, transfer the cookies to a wire rack to completely cool. Store in a closed container at room temperature for up to 4 days. Enjoy!
