- Preheat oven to 350°F.
- Beat butter and powdered sugar in large mixer bowl until creamy.
- Beat in vanilla extract.
- Gradually beat in flour and nuts.
- Stir in 1½ cups morsels.
- Roll dough into 1-inch balls; place on ungreased baking sheets.
- Bake for 10 to 12 minutes or until set and light golden brown on bottom.
- Cool for 2 minutes on baking sheets; remove to wire racks to cool completely.
- Microwave remaining morsels in heavy-duty plastic bag on high (100%) power for 30 to 45 seconds; knead.
- Microwave at additional 10- to 20-second intervals, kneading until smooth.
- Cut tiny corner from bag; squeeze to drizzle over cookies.
- Refrigerate cookies for about 5 minutes or until chocolate is set.
- Store at room temperature in airtight containers.
- Note: for a spicier cookie, add 2 to 2½ teaspoons ground cinnamon to flour before adding to butter-sugar mixture.