1Heat oven to 375°F. Line cookie sheets with cooking parchment paper.
2In medium bowl, mix flour, baking soda and salt; set aside. In large bowl, beat butter, granulated sugar and brown sugar with electric mixer on medium speed until creamy. Add pumpkin and egg; beat until well blended. Gradually beat in flour mixture. Stir in oats, nuts and 1 cup of the white chips. Onto cookie sheets, drop dough by rounded tablespoonfuls about 2 inches apart. Bake 12 minutes or until lightly browned. Remove from cookie sheets to cooling racks; cool completely.
3In small microwavable bowl, microwave remaining 1 cup white chips uncovered on High 1 minute, stirring once, until softened and chips can be stirred smooth. Drizzle over cookies. Place on waxed paper; let stand until set.