Preheat oven to 350℉. Line a sheet pan with parchment paper or a silicon baking mat.
In a small bowl, combine brown sugar, granulated sugar, vanilla, vegetable oil, egg yolk, and pumpkin. Mix until smooth. (See note 1.)
Add salt, baking powder, pumpkin pie spice, cinnamon, flour, and chocolate chips. Stir until smooth.
Use a tablespoon measure to scoop 4–5 small cookies out of the dough on to the prepared sheet pan. The dough will be sticky. Bake 8–10 minutes or until no longer glossy on top.
Remove from oven and let stand on the cookie sheet for 3–5 minutes, then transfer to a cooling rack. If desired, press a few more chocolate chips into the tops of the cookies. Let cool before eating.
Notes
Note 1: Make sure to measure precisely. With such small quantities, the proportions are very important. (Don’t loosely measure on this recipe.)Storage: To store these small batch pumpkin cookies, keep them in an airtight container at room temperature for up to 3 days.If you have extra dough, freeze it as individual dough balls for up to 3 months—just bake them from frozen, adding 2-3 minutes to the bake time.