COAT 13 x 9-inch baking pan with nonstick cooking spray.
COMBINE cereal, pretzels, peanuts and caramels in large bowl.
MICROWAVE morsels in medium, uncovered, microwave-safe bowl on MEDIUM-HIGH (70%) power for 1 minute; STIR. Morsels may retain some of their original shape. If necessary, microwave at additional 10- to 15-second intervals, stirring just until morsels are melted. Pour over cereal mixture; stir to coat evenly.
SPREAD mixture in prepared baking pan; cool for 30 to 45 minutes or until firm. Break into bite-size pieces. Store in airtight container.