Prep your tools and oven. Heat the oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone mats. This prevents sticking and ensures even baking.

Blot the pumpkin. Pumpkin holds a lot of water. Spoon the pumpkin puree onto a few layers of paper towel or a clean kitchen towel. Gently press to remove excess moisture for about 30 seconds. You don’t need it bone-dry, just less wet.

Cream the butter and sugars. In a large bowl, beat the softened butter with the brown and white sugars until smooth and fluffy, about 2 minutes. This step helps with texture and flavor.

Add wet ingredients. Mix in the egg yolk (if using) and vanilla until combined. Stir in the blotted pumpkin puree. The mixture might look slightly curdled—totally normal.

Whisk dry ingredients. In a separate bowl, whisk the flour, baking soda, baking powder, salt, cinnamon, and pumpkin pie spice until evenly mixed.

Combine wet and dry. Add the dry ingredients to the wet mixture. Stir gently until just combined. Don’t overmix or the cookies can turn tough.

Fold in chips (and nuts). Stir in the chocolate chips and nuts if using. The dough will be thick and a bit sticky.

Portion the dough. Use a 1 1/2-tablespoon scoop to drop mounds onto the prepared sheets, spacing them 2 inches apart. Press a few extra chocolate chips on top for a bakery-style look.

Bake. Bake for 10–12 minutes, until the edges look set and the tops have lost their wet sheen. The centers should still be soft.

Cool. Let cookies cool on the sheet for 5 minutes, then move to a rack. They’ll continue to set as they cool, staying soft and cakey.