MICROWAVE morsels and peanut butter in medium, uncovered, microwave-safe bowl on MEDIUM-HIGH (70%) power for 1 minute; STIR. The morsels may retain some of their original shape. If necessary, microwave at additional 10- to 15-second intervals, stirring just until morsels are melted.
DIP about 3/4 of one pretzel in butterscotch mixture; shake off excess. Place on wire rack; sprinkle lightly with sesame seeds. Repeat with remaining pretzels. (If mixture thickens, microwave on MEDIUM-HIGH (70%) power at 10- to 15-second intervals, stirring until smooth).
REFRIGERATE for 20 minutes or until set. Store in airtight containers or resealable plastic bags.