01 -  Preheat oven to 350°F. Line a large baking sheet with parchment paper. 
 02 -  Whisk flour, sugar, baking powder, baking soda, salt, ginger, cinnamon, nutmeg, and cloves in a large mixing bowl until evenly blended. 
 03 -  In a separate bowl, beat eggs. Whisk in pumpkin puree, molasses, vegetable oil, and vanilla extract until mixture is smooth. 
 04 -  Pour wet mixture into dry ingredients and mix just until evenly incorporated. 
 05 -  Gently fold in chopped nuts and chocolate chips if using. 
 06 -  Divide the dough in half. With floured hands, shape each half into a log about 12 inches long and 2 inches wide. Place logs on prepared baking sheet, spaced apart. 
 07 -  Flatten logs to about 3/4 inch thickness. Bake for 25–28 minutes until golden and firm. 
 08 -  Remove baking sheet from oven. Allow logs to cool for 15 minutes on the pan. 
 09 -  Adjust oven temperature to 300°F. Transfer logs to cutting board. Using a serrated knife, slice diagonally into 1/2-inch pieces. 
 10 -  Arrange sliced pieces cut side down on baking sheet. Bake for 12 minutes, then flip and bake 10–12 minutes more, until dry and crisp. 
 11 -  Transfer biscotti to a wire rack and cool completely before serving or storing.