In a large mixing bowl, cream together butter and sugars.
Add pumpkin, egg, and vanilla, beating until combined.
In another large bowl, combine flour, baking powder, baking soda, cinnamon, pumpkin pie spice, clove, and ginger.
Add dry ingredients to pumpkin mixture and beat until just combined. Do not overmix, or you'll end up with tough cookies!
Fold in pecans, dried cranberries, and white chocolate chips.
Drop by tablespoonfuls onto parchment paper or silicone mat-lined cookie sheets.
Bake at 350 degrees for 10-12 minutes, or until edges are lightly browned and centers are set.
Remove cookies to a wire rack. Cool completely.
In a small microwave-safe bowl, heat white baking chocolate for 30 seconds. Stir, and heat again for 15-second intervals, stirring in-between, until melted and smooth.
Drizzle over cookies. Allow to set. Store cookies in airtight containers at room temperature for about 5 days.