Preheat oven to 325 degrees. Line baking sheet with parchment paper.

In a large bowl, beat butter and sugar until light and fluffy. Beat in egg, vanilla and pumpkin. In a small bowl, combine flour, baking powder, salt, cinnamon, nutmeg, and ginger. Add in batches to pumpkin mixture until well combined. Stir in white chocolate and pecans. Shape dough into 2 (14-inch x 1 1/2-inch) slightly flattened logs. Place 2 inches apart on parchment lined baking sheet.

Bake 25 minutes or until lightly browned. Place on a cutting board: cool 5 minutes. Using serrated knife, cut each log into diagonal slices about 3/4-inch thick. Place slices upright on baking sheet. Bake 10 minutes or until slightly dry. Cool on wire racks.

Melt 8 squares of white chocolate. Dip 1/2 of each biscotti into melted chocolate and transfer to parchment lined baking sheet. Sprinkle with chopped pecans.