Preheat the oven to 350 degrees F

Line two baking sheets with parchment paper or silicone baking mat

In a large bowl, beat together butter and brown sugar until smooth and creamy

Add the pumpkin, eggs, and vanilla extract and beat until well combined

In a medium bowl, whisk together flour, baking powder, salt, and spices

Gradually add dry ingredients to the pumpkin mixture until well incorporated

Stir in chocolate chips and walnuts, if using

Using a cookie scoop or a spoon, drop the dough onto the prepared baking sheets

Bake at 350 degrees F for 10-12 minutes, or until the edges of the cookies are lightly browned.

Remove from the oven and let cookies cool on baking sheets for 5 minutes before transferring to cooling racks

Place cookies in an airtight container and store for several days at room temperature; freeze for longer storage