1. Heat oven to 350°F. Place butter in 13x9x2-inch baking pan. Heat in oven until melted; remove pan from oven. Sprinkle graham cracker crumbs evenly over butter; press down with fork.
2. Sprinkle peanut butter chips over crumbs; sprinkle coconut over chips. Drizzle sweetened condensed milk evenly over top.
3. Bake 20 minutes or until lightly browned.
4. Combine chocolate chips and shortening 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, just until chips are melted and mixture is smooth. Drizzle evenly over top of baked mixture. Cool completely. Cut into bars. About 48 bars.