1. Heat oven to 350°F. Grease 15-1/2x10-1/2x1-inch jelly-roll pan.
2. Stir together brown sugar and butter in large bowl; beat in eggs and vanilla until smooth. Add flour and salt, beating just until blended; stir in chocolate, peanut butter and white chips. Spread batter in prepared pan.
3. Bake 25 to 30 minutes or until wooden pick inserted in center comes out clean. Cool completely; cut into bars. With tines of fork, drizzle CHOCOLATE CHIP DRIZZLE randomly over bars. About 4 dozen bars.
CHOCOLATE CHIP DRIZZLE: Place 1/4 cup HERSHEY'S SPECIAL DARK Chocolate Chips or HERSHEY'S Semi-Sweet Chocolate Chips and 1/4 teaspoon shortening (do not use butter, margarine, spread or oil) in small microwave-safe bowl. Microwave at MEDIUM (50%) 30 seconds; stir. If necessary, microwave at MEDIUM an additional 10 seconds at a time, stirring after each heating, until chips are melted and mixture is smooth.