CHOP 8 of the chocolate squares; place in microwaveable bowl. Add cream and butter. Microwave on MEDIUM 1-1/2 min.; stir until chocolate is completely melted. Cover. Refrigerate 1 hour or until firm. Meanwhile, cover baking sheet with waxed paper.
SHAPE chocolate mixture into 24 balls, using about 1 tsp. for each ball. Place in single layer on prepared baking sheet.
MELT remaining 8 chocolate squares as directed on package. Dip chocolate balls, one at a time, in melted chocolate. Return to baking sheet. Sprinkle with walnuts. Refrigerate until chocolate is firm. Store in tightly covered container in refrigerator.