Preheat oven to 325 degrees F. For cookies, place 1/2 cup walnuts and the cocoa in work bowl of food processor or blender. Process until nuts are finely chopped; set aside. Cream butter and sugars in small mixing bowl until light and fluffy. Stir in flour and nut mixture; mix well.

Shape dough into 1-inch balls. Place 2 inches apart on unbuttered cookie sheets. Flatten to about 1-1/2-inch diameter using a flat bottom glass dipped in granulated sugar. Bake 20 to 25 minutes or until edges of cookie are firm but center is still soft when lightly pressed. Cool on cookie sheets 2 to 3 minutes. Transfer cookies to wire racks; cool completely.

For glaze, place chocolate in small microwave-safe bowl. Microwave on HIGH 2 to 2-1/2 minutes, stirring every 15 seconds. Remove from microwave just before chocolate is completely melted. Stir in butter, 1 Tbsp at a time, until melted. Stir in corn syrup and vanilla. Spread small amount of glaze on each cookie. Sprinkle with remaining 3/4 cup walnuts. Refrigerate cookies 30 minutes or allow glaze to set at room temperature overnight. Store in cool place in airtight metal containers upt o 3 weeks. Freeze up to 6 months.

Recipe Courtesy of The American Butter Institute.