In a extra large bowl, toss together cereals, pretzels, and peanuts.
Dump mix onto a large rimmed baking sheet and top with M&M's.
Place the white chocolate chips in a microwave safe bowl and melt on high power for 60 seconds in microwave or melt over a double boiler.
Stir the chips well to finish melting and make it smooth. If any large chunks remain continue melting in 20 second increments, stirring often.
Immediately drizzle over the cereal mixture.
Quickly sprinkle with holiday sprinkles.
With a spoon toss the mixture to distribute the chocolate. Working quickly before chocolate sets.
Allow to cool for 15 minutes.
Break apart and SERVE!
Notes
Evenly add the sprinkles the moment you are done drizzling on the white chocolate so that it sticks to the chocolate. Otherwise the chocolate will start to set and the sprinkles will just fall off.
Mixing the melted white chocolate into the mix on a large tray or baking sheet is easiest so that you can quickly and evenly distribute the melted chocolate before it starts to set.
Store leftover chex mix in an airtight container on the counter for up to 4 days.
Recipe adapted from https://www.chex.com/recipes/christmas-chex-party-mix