1Spray 24 regular-size muffin cups with cooking spray. In large microwavable bowl, microwave marshmallows and butter uncovered on High 1 minute; stir. Continue to microwave in 30-second increments, stirring until smooth. Stir in peanut butter until blended. Gradually stir in cereal, pretzels and peanuts until well mixed.
2Divide cereal mixture evenly among muffin cups, pressing mixture in bottom and up side of each cup to form nest, using lightly buttered hands. Let stand until set, about 30 minutes.
3Remove nests from muffin cups. Place about 3 malted milk eggs in each nest.