Position racks in top and bottom of oven and preheat to 350 degrees. Prepare baking sheets by lightly coating with butter and a dusting of flour.
In a medium bowl, whisk together the flour, baking soda, and spices; set aside.
In a large mixing bowl, cream the butter with an electric mixer until softened. Add the brown sugar and granulated sugar and beat until light, but still grainy.
Add the egg and egg white and mix until smooth. Mix in the pumpkin and vanilla. (The batter will look curdled at this point.)
Using a wooden spoon, fold in the flour mixture until incorporated. Don't overdo it so that the batter to becomes sticky. Gently stir in the chocolate chips and hazelnuts (or any other nuts).
Drop by rounded tablespoons 2 inches apart onto the two baking sheets. Bake for 10 minutes—one on the top rack and one on the bottom rack—then switch the pans top to bottom and front to back. Continue baking 10-12 minutes until slightly browned. Cool on the baking sheets for 2 minutes before removing to wire racks. Continue baking additional batches until all the dough is used up.
Cool cookies completely before storing in airtight containers. If desired, top cookies with marshmallow creme and serve. (Cookies will be difficult to store when topped with marshmallow creme—too sticky—but they are fun to eat this way if serving right away.)
Original recipe from The Ultimate Chocolate Cookie Book, 2004