In microwave, heat white-chocolate chips on medium heat for 30 seconds, stir, and then return to microwave for 30 seconds more. Stir until smooth. Transfer to small resealable plastic bag, and snip off one corner. Pipe out spider-web design on bars or Bon Bons. If desired, attach spider-shaped candy and red M&Ms dotted with black decorating icing (to resemble ladybug) to ice cream bar, in center of web.