Preheat the oven to 350°F. Line a baking sheet with parchment paper or a silicone baking mat.
Add pumpkin, sugar, vegetable oil, vanilla, and egg in a large bowl and mix until smooth. In a small measuring cup, combine the baking soda and milk, stirring till the baking soda dissolves. Add this mixture to the other wet ingredients.
In a separate bowl, whisk together the flour, baking powder, cinnamon, pumpkin pie spice, and salt.
Add the flour mixture to the pumpkin mixture and stir until the flour disappears, being careful not to overmix. Gently fold in the chocolate chips.
Drop cookies by rounded spoonful about 2 inches apart on the baking sheet.
Bake 10-14 minutes. The cookies are done when a toothpick inserted in the center comes out clean and the bottoms are lightly brown.
Let cool on the baking sheet for about 5 minutes, then transfer to a cooling rack to cool completely.