In large bowl, combine cereals, peanuts, and pretzels.
In medium saucepan, combine corn syrup, brown sugar, and butter in saucepan, and bring to boil over medium heat.
Boil 3 minutes, stirring constantly. Stir in vanilla.
Immediately pour sugar mixture over cereal mixture, and stir well to coat. Stir in M&M'S®.
Using a greased spatula, press mixture tightly into a greased jellyroll pan, and cool at room temperature.
Cut into bars when completely cooled.
Submitted by: Shelly Hoff