Line a large sheet pan with parchment paper and set it aside.

In a large bowl, combine corn Chex, pretzels, Lucky Charms cereal, Lucky Charms marshmallows, and 1/2 cup of the green M&M’s.

In a microwave-safe bowl, add the white chocolate chips and vegetable oil. Microwave for 30 seconds, stir, and microwave for another 25 seconds. Stir until the mixture is melted and smooth. If needed, return to the microwave for 10-second bursts, stirring between each burst.

Pour the melted white chocolate over the snack mix.

Gently stir until everything is completely combined. Transfer the mix to the prepared sheet pan and spread it into an even layer.

Add the remaining 1/4 cup of M&M’s on top.

Allow the mix to harden at room temperature or place it in the fridge until firm, which takes about 10 to 20 minutes. Break the hardened mix into pieces before serving or package it into bags.