Preheat the oven to 350ºF degrees. Line a large baking sheet with parchment paper or a silicone baking mat. Lightly flour the baking sheet. Set aside.
In a medium size bowl, whisk together the butter, pumpkin, egg, and sugar until combined. Set aside.
Add the wet ingredients to the dry ingredients and gently mix with a large wooden spoon or sturdy rubber spatula until everything starts to come together. Mixture will be crumbly. This is ok. It will come together in the next step.
Check out this Instagram reel to see how I make my biscotti. Turn dough out onto lightly floured baking sheet and, with floured hands, pat dough into a rectangle about 1/2" thick. My rectangle was 6" wide and 7 and 1/2" long (using a ruler or a ruled silicone baking mat is helpful here). Sprinkle with prepared sugar/spice coating.
Bake dough slab for 20-22 minutes, or until the top and sides of the slab are lightly browned. Remove from the oven, but do not turn off the heat. Place baking sheet on a wire rack and allow to cool for 10 minutes.
Once the dough is cool enough to touch, cut into 1" thick slices using a sharp knife. Cut these 1" slices in half, making a perpendicular slice down the entire slab. Set slices cut sides up on the baking sheet.
Return to the oven to bake for 6 minutes. Remove from oven, turn biscotti over, and bake the other side for 6 minutes. Remove from the oven and allow to cool for 3 minutes on the baking sheet (cookies will become crunchy as they cool). Transfer biscotti to a wire rack to cool completely. Cookies stay fresh covered tightly at room temperature up to 7 days. Cookies freeze well, up to 2 months. Thaw at room temperature.
Nutrition Disclosure
All nutritional values are approximate and provided to the reader as a courtesy. Changing ingredients and/or quantities will alter the estimated nutritional calculations.