Preheat oven to 375 degrees. In a small bowl, mix together flour and walnuts. Set aside.
In a medium saucepan, bring corn syrup, butter and brown sugar to a boil over medium heat, stirring constantly. Remove from heat and stir in flour/walnut mixture. Let cool one minute.
Drop level tablespoons of batter 3 inches apart on lightly buttered baking sheet. Batter will be slightly runny. Bake about 5 minutes, or until cookies are lightly golden around the edges (batter will spread and get all bubbly, forming 'holes' like lace). Let stand about a minute until firm enough to handle. Loosen all cookies first with a spatula, then remove to cooling racks.
Option: Brush the tops with melted dark or white chocolate and let stand until chocolate hardens.