In a medium bowl mix together flour, baking soda, salt, cinnamon, and pumpkin pie spice. Set aside.
In the bowl of an electric stand mixer, cream together butter and brown sugar for 1 minute until light and fluffy. Scrape down the sides of the bowl.
With the mixer on low, add in the egg and mix until combined. Scrape down the sides again.
Add in vanilla, milk, and pumpkin pureé. Mix to combine. With the mixer on low speed, gradually pour in flour. This should take about 20 seconds. Only mix to combine.
Do not leave mixer running. Use a spatula to fold in chocolate chips. Wrap dough in plastic wrap and refrigerate overnight until firm and cold to touch.
Line a baking sheet with parchment paper. Set aside.
Preheat oven to 350 degrees F. Remove dough from refrigerator. Roll dough into balls 2 tablespoon in size. Place on cookie tray 2 inches apart.
Do not press the cookies down. Bake at for 8 minutes. Remove cookies from oven and firmly bang the tray on the counter. This will help the cookies flatten. Put back into the oven for 4 more minutes or until the tops of the cookies are no longer shiny. They will appear slightly under cooked.
Allow them to cool for 3 minutes on the tray before moving to the cooling rack.
Sprinkle with a dusting of pumpkin pie spice. Eat!