In a small bowl, combine ½ cup peanut butter, butter, powdered sugar and salt until smooth; set aside. In a small microwave safe bowl, melt chocolate chips, candy bars and remaining peanut butter; stir until smooth. Drop a teaspoonful of the chocolate mixture into paper-lined miniature muffin cups. Top each with a scant teaspoonful of peanut butter mixture; top with another teaspoonful of chocolate mixture. Decorate with sprinkles if desired. Refrigerate until set. Store in an airtight container. Yields 3 dozen.