Preheat oven to 350°. Line a large baking sheet with parchment paper; lightly dust with flour.
In a large bowl, beat flour, sugar, pumpkin pie spice, salt, baking powder, and baking soda with a mixer at low speed until combined.
In a medium bowl, whisk together eggs, pumpkin, and vanilla. Add pumpkin mixture to flour mixture, beating until smooth dough forms. Beat in cinnamon morsels. Divide dough in half, place on prepared pan. Shape each half into a 15x4-inch log.
Bake until center is firm to the touch, about 30 minutes. Let cool for 15 minutes. Reduce oven to 300°. Line a large baking sheet with parchment paper.
Using a serrated knife, cut logs into ¾-inch pieces, lay on side of prepared pans. Bake until firm to the touch, about 15 to 20 minutes. Let cool completely.
In a small microwave-safe bowl, heat white chocolate on high in 15-second intervals, stirring between each, until melted. Dip end of biscotti in melted chocolate, and place on parchment paper to let cool. Garnish with nutmeg before chocolate has hardened, if desired.
Recipe by The Ribbon in My Journal - Phyllis Hoffman DePiano at https://www.theribboninmyjournal.com/pumpkin-spice-biscotti/