Preheat your oven to 350°F (175°C). Line two large baking sheets with parchment paper or lightly grease them.

In a large mixing bowl, combine the pumpkin puree, granulated sugar, vegetable oil, and vanilla extract. Whisk until the mixture is smooth.

Add the egg to the pumpkin mixture and beat well until fully incorporated.

In a medium bowl, whisk together the flour, baking powder, ground cinnamon, and salt.

In a small cup, dissolve the baking soda into the teaspoon of milk. Stir this into the wet pumpkin mixture.

Gradually add the dry flour mixture to the wet ingredients. Stir with a large spoon or spatula until just combined. Do not overmix.

Gently fold in the semi-sweet chocolate chips until they are evenly distributed throughout the batter.

Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.

Bake for 10 to 12 minutes in the preheated oven. The cookies should look set but still feel soft to the touch.

Let the cookies cool on the baking sheet for 5 minutes before moving them to a wire rack to cool completely.