Preheat the oven to 350˚F (180°C). Grease a 9"×13" (22x33 cm) pan and set aside.
Add the flour, baking soda, salt, cinnamon, and pumpkin pie spice to medium-sized mixing bowl and whisk until combined.
Add the butter and sugars to a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment. Beat with a hand mixer or the stand mixer until light and fluffy.
Add the pumpkin, milk, and vanilla and beat until well combined.
Add the dry mixture to the wet and mix until just combined.
Fold in the chocolate chips.
Press the cookie dough evenly into the prepared pan.
Bake in the preheated oven for 18-22 minutes, until a toothpick comes out clean or with just crumbs.
Allow to cool slightly and slice into 24 bars.