Method

• Position oven racks in the upper and lower thirds and preheat the oven to 375°F (190°C) for approximately 15 minutes. Line two 18 x 13-inch (46 x 33 cm) baking sheets with parchment paper. The oven should be fully heated before baking so the cookie edges begin setting promptly.
• In the medium mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, cinnamon, and ginger for 30–45 seconds. Continue until the spices and leavening agents are evenly distributed and the flour mixture has a uniform color.
• Place the softened butter, brown sugar, and granulated sugar in the large mixing bowl. Beat with an electric mixer on medium speed for 2–3 minutes, scraping down the bowl as necessary, until the mixture looks smooth, lighter in color, and slightly fluffy. This distributes the sugar throughout the fat for even texture.
• Add the pumpkin purée, egg, and vanilla extract to the creamed mixture. Beat on low to medium speed for approximately 1 minute, until thoroughly combined. The mixture should be uniformly orange and may appear slightly curdled because the pumpkin contains considerable moisture.
• Add the dry ingredients to the pumpkin mixture in two additions. Mix on low speed for approximately 30–60 seconds, stopping as soon as no dry flour remains. The dough should look thick, soft, and slightly sticky. Avoid extended mixing because excessive gluten development can toughen the cookies.
• Add the semisweet chocolate chips and fold them into the dough with a silicone spatula for approximately 30 seconds. Scrape the bottom and sides of the bowl until the chips are evenly distributed. The finished dough should be thick enough to hold a soft mound when scooped.
• Use a tablespoon cookie scoop to divide the dough into approximately 30 portions, distributing them evenly between the prepared baking sheets. Leave about 2 inches (5 cm) between the portions to allow for spreading. Keep the mounds approximately the same size so they bake at a similar rate.
• Place both baking sheets in the preheated 375°F (190°C) oven. Bake for 17–19 minutes, exchanging the upper and lower sheet positions and turning the sheets front to back halfway through. The cookies are ready when their edges are lightly golden, their surfaces look set rather than wet, and the centers feel springy when gently touched.
• Remove the baking sheets from the oven and let the cookies rest on them for 5 minutes. The residual heat helps their delicate structure finish setting. Transfer the cookies to a wire cooling rack using a spatula. Allow them to cool further until the bottoms are firm and the chocolate is no longer excessively hot.