Sprinkle half of the peanuts into a greased 13-in. x 9-in. baking pan. In a large microwave-safe bowl, heat chips and butter at 50% power for 1 minute; stir. Microwave in 20-second intervals until melted; stir until smooth. Stir in sweetened condensed milk; cook, uncovered, on high for 1 minute.
Stir in marshmallow creme and candy bars. Spread into prepared pan. Sprinkle with remaining peanuts. Cover with plastic wrap; press down lightly.
Refrigerate until set. Cut into 1-in. squares. Store in an airtight container.