Line a baking sheet with parchment paper. Place the white chocolate chips and coconut oil in a microwave safe bowl. Microwave for 30 seconds at a time, stirring after each, until the chocolate is melted.
Note: if you don’t have coconut oil, you can leave it out. I find that it makes the white chocolate firm up a bit more, but it’s not 100% necessary!
Mix the Cherrios, Chex, pretzel sticks and cashews on the baking sheet. Toss them gently. Add on half of each version of m&m’s. Drizzle the mixture all over with the white chocolate. Use a spatula or large spoon to gently (and somewhat quickly) toss the mix together, until all of the pieces are coated. Sprinkle in the remaining m&m’s and gently toss once more. If desired, sprinkle the entire sheet with the shredded coconut. You can also sprinkle on more white chocolate chips if you wish!
Let the mixture set for 20 to 30 minutes. Transfer to a large bowl or jar that you can cover or a resalable plastic bag. You can definitely make this a day or two ahead of time!