1. Heat oven to 350°F. Melt 1/2 cup margarine in medium saucepan; stir in crumbs, walnuts, sugar and cocoa. Press firmly on bottom of ungreased 13x9x2-inch baking pan.
2. Beat cream cheese, remaining 2 tablespoons margarine and cornstarch in small bowl until fluffy. Gradually beat in sweetened condensed milk then egg, peppermint extract and food color, if desired. Pour evenly into prepared pan.
3. Bake 25 minutes or until center is set. Cool. Drizzle CHOCOLATE DRIZZLE over top. Refrigerate until thoroughly chilled. Cut into bars. Store covered in refrigerator. Makes about 24 bars.
CHOCOLATE DRIZZLE: Melt 1 cup HERSHEY'S SPECIAL DARK Chocolate Chips or HERSHEY'S Semi-Sweet Chocolate Chips with 1-1/2 teaspoons shortening (do not use butter, margarine, spread or oil).