Lay out 1 large sheet of parchment paper to set the puppy chow for drying a few minutes after all mixed
Measure 6 cups of Chex cereal into a large bowl
Measure 1/2 cup of powdered sugar into a large sealable baggie
Unwrap 8 to 10 regular size peppermint candy canes, place in a ziploc baggie, crush with a rolling pin ~leaving several 1/8 to 1/4 inch pieces of candy cane. There should be various pieces of candy cane from fine dust to 1/8 inch pieces. Measure into a bowl, crushing more candy canes as needed. **
Measure M&Ms into a bowl
In a microwave proof bowl, measure 1 1/2 cups white vanilla chips. Add 2 tsp of peppermint extract. Microwave for 30 seconds at 80% power, stir with a rubber spatula. Repeat up to 2 or 3 more times, stirring in between each cycle. Once most of the chips are melted/softened, stir until all chips are completely smooth.
Pour and scrape softened vanilla chips over the Chex cereal, mix gently with rubber spatula until all cereal is coated
Pour all cereal into ziploc baggie with powdered sugar. Seal bag and shake to coat cereal with the powdered sugar.
Add crushed peppermint candy and M&Ms. Shake to combine.
Pour onto parchment paper to cool and dry. Store in airtight container up to 1 week.