In large microwave safe bowl, melt candy at 50% power for 1 minute; stir. Continue microwaving in 30 second intervals until candy is completely melted.

In large bowl, combine cereal and melted candy; fold until evenly coated. Pour cereal into a large re-sealable plastic bag; add confectioners' sugar and nonpareils. Shake until cereal is evenly coated. Spread out on cookie pan to set.