In a large roasting pan, or large casserole dish, mix all ingredients except the M&M's, sprinkles, and candy melts. Do not over fill your dish, you will need room to toss the ingredients together.

Melt white chocolate (or candy melts) in a microwave safe dish (at 50% power) in 30 second intervals until almost melted. Stir until completely melted and smooth. Use a spoon to drizzle the melted chocolate over the dish of snacks. Mix as needed to coat. It's up to you if you want the mix to be totally coated, or lightly coated (depending on the amount of melted chocolate you use). As soon as you've mix up the snack mix, but the coating is still warm and melty, add sprinkles of your choice, and M&M's to the mix. Stir to combine.

Spread the snack mixture out onto a baking sheet (or two if needed). Allow to cool, then break apart as needed.

If desired, add some of the melted white chocolate to a small plastic piping bag (or small ziplock bag), snip off the end and drizzle over the mix, then allow the chocolate to set before packaging up the mixture.

Store snack mix in an airtight bag or container.

Snack mix with popcorn in it will remain fresh tasting about 2-3 days, and a bit longer without popcorn.