Combine cereal, pretzels, peanuts and M&M’s in a very large bowl (I usually divide everything evenly between two bowls so I don’t make a mess stirring).
Line two baking sheets with wax or parchment paper; set aside.
Melt vanilla chips and oil over simmering heat in a double boiler. OR Combine white chocolate chips and oil in a microwave-safe bowl then heat and stir at 30-second intervals until chocolate is melted. Be very careful not to overheat the melted mixture as it can "seize up" if it starts to burn.
Pour melted chocolate over dry ingredients then gently fold until well combined. Spoon mixture onto baking sheets, spread to cover pans then add jimmies on top
Cool in the refrigerator until set. Break cooled mixture into chunks then store in an air-tight container at room temperature
