1In large bowl, combine cereals. Add marshmallows; toss to mix. Spread mixture on sheet of waxed paper.
2In small microwavable bowl, microwave chocolate chips on Medium (50%) 1 minute. Stir until chips are melted and mixture is smooth. If needed, microwave 15 to 30 seconds longer on Medium.
3Using spoon or fork, drizzle melted chocolate over cereal-marshmallow mixture. Let stand about 1 hour or until chocolate is set.