Preheat oven to 350 degrees.
Stir crumbs and butter together in small bowl.
Press onto bottom of 9 inch square baking pan.
Bake at 350F for 10 to 15 minutes. Cool.
Beat cream cheese, peanut butter and sugar in small bowl with electric mixer until well blended.
Spread over crust.
Microwave chocolate with butter on high 1 to 2 minutes or until chocolate begins to melt, stirring every 20 seconds.
Stir until chocolate is completely melted.
Drizzle chocolate over cream cheese mixture.
Refrigerate 6 hours or overnight.
Cut into squares.
Store air tight in refrigerator.