Preheat oven to 375°F (190°C). Line baking sheets with parchment paper.

In a medium bowl, whisk together flour, baking soda, pumpkin pie spice, and salt.

In a large bowl, whisk the melted butter, brown sugar, and granulated sugar until well combined.

Whisk in the pumpkin puree, egg, egg yolk, and vanilla extract until smooth.

Gradually add the dry ingredients to the wet ingredients and mix with a spatula until just combined. Do not overmix. If using, fold in optional chocolate chips or nuts.

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

Bake for 10-12 minutes, or until the edges are golden brown and the centers are set.

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