PREPARE cake mix batter according to package directions; add chopped Butterfinger to batter. Bake according to directions for 24 cupcakes. Cool completely. Frost cupcakes.
PLACE morsels in small, heavy-duty plastic bag. Microwave on HIGH (100%) power for 45 seconds; knead. Microwave at additional 10- to 15-second intervals, kneading until smooth. Cut small corner from bag; squeeze to pipe concentric circles on top of frosting. Using wooden pick or tip of knife, pull tip through chocolate from center to last circle to create a cobweb effect.
MAKE 2 dots using decorator icing on each of 24 Goobers to resemble spider eyes. Place in center of each cobweb.
VARIATION: Substitute vanilla frosting with chocolate frosting. Substitute melted chocolate morsels with 2 small tubes white decorator icing or gel.