Preheat oven to 375 degrees F and line a baking sheet with parchment paper. Set aside.
In a small bowl, combine flour, pumpkin pie spice, cinnamon and baking powder. Mix well and set aside.
In a larger mixing bowl, combine sugar, pumpkin puree, eggs, butter and molasses and mix well. Add the dry ingredients to the wet and mix until combined. Dough will be sticky.
Onto a generously floured surface (approximately ¼ cup flour) place dough and knead incorporating additional flour until dough is no longer sticky.
Divide dough in half and place onto the prepared baking sheet. Shape dough into a long rectangle/log about 10" long and ½" thick. Dough will be about 3-4" wide.
Bake for 25 minutes. Remove from oven and let cool for 10 minutes. Use a bread or serrated knife to cut biscotti into 1" sections. Place biscotti, cut side down on parchment paper and return to the oven for 15-20 minutes, flipping biscotti halfway between cooking. Biscotti should be browned on the cut edges.
Remove from oven and let stand to cool completely.
If desired, place white chocolate into a resealable sandwich bag and microwave for 30 seconds at 50% powder, kneading bag after microwaving. If chocolate is not melted, return to the microwave, heating for 20 seconds at 50% powder kneading until smooth. Drizzle on top of the cut side of the biscotti. Let stand to cool completely.
Serve with your favorite cup of coffee and store any leftover biscotti in a sealed container
Makes about 20 biscotti.