COMBINE cereal, popcorn, pretzels and peanuts in large microwaveable bowl; set aside.
MIX butter, mustard, honey, garlic powder and onion powder until well blended. Drizzle over cereal mixture; toss to coat.
MICROWAVE on HIGH 2 to 3 min. or until cereal is crisp, stirring after 2 min. Cool completely.
