Preheat your oven to 350°F (175°C). Line two baking trays with parchment paper. This helps prevent the cookies from sticking and promotes even baking.
In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, ginger, nutmeg, and salt. Set aside while preparing the wet ingredients.
In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar until creamy and well combined. This should take approximately 2–3 minutes using an electric mixer.
Mix in the egg yolk, pumpkin puree, and vanilla extract until smooth. The egg yolk helps provide structure, while the pumpkin adds moisture and flavor.
Gradually add the dry ingredients to the pumpkin mixture. Stir gently until the flour is almost fully incorporated. Add the chocolate chips and fold them into the dough. If using chopped nuts, add them at this stage.
Refrigerate the dough for 20–30 minutes if it feels soft or sticky. Pumpkin puree adds moisture, so chilling can make the dough easier to scoop and help the cookies hold their shape during baking.
Scoop approximately 1½ tablespoons of dough for each cookie and place the portions on the prepared trays, leaving about 2 inches between them. Press a few extra chocolate chips gently onto the tops for an attractive appearance.
Bake for 10–14 minutes, depending on cookie size. The edges should look set, while the centers may remain slightly soft. Avoid overbaking, as the cookies will continue to firm up as they cool.
Allow the cookies to rest on the baking tray for about 5 minutes before transferring them to a wire rack. Let them cool further before serving so the centers can set.
Serve the cookies warm for soft centers and slightly melted chocolate, or let them cool completely for easier storage. Pair them with milk, coffee, tea, or hot chocolate for a delicious homemade treat.