Melt the butter and let it cool until no longer warm. Whisk it with the brown sugar and granulated sugar, then whisk in the pumpkin puree and vanilla.

Whisk the flour, baking soda, baking powder, salt, and cinnamon in another bowl. Fold into the pumpkin mixture just until combined, then fold in the chocolate chips. Cover and refrigerate for 30 minutes, or until scoopable. Do not taste the raw dough.

While the dough chills, heat the oven to 350°F. Line two large baking sheets with parchment. Divide the dough into 24 portions, about 30 g or 1 1/2 tablespoons each. Arrange 12 per sheet with about 2 inches between portions and flatten the tops slightly. Keep the second tray chilled while the first bakes.

Bake one sheet at a time on the center rack for 11–13 minutes per batch, until the edges are set and lightly browned and the centers no longer look wet. Rotate the sheet if your oven browns unevenly. The cookies will still feel soft when hot.

Cool each batch on its baking sheet for 10 minutes, then move to a wire rack for at least 5 more minutes. Cool completely before storing airtight for up to 3 days at cool room temperature, or freeze for up to 2 months.