Pour the Rice Chex into a very large mixing bowl. You can also use a doubled clean paper bag if you want to shake the mixture instead of tossing it in a bowl.

Add the sweetened condensed milk, melted butter, and white chocolate or cream cheese chips to a microwave-safe bowl. Heat for 30 seconds, stir well, and continue heating in short intervals until the chips are melted and the mixture is smooth.

Stir the dry pistachio pudding mix into the warm mixture until completely blended. Add the vanilla and salt and give everything another good stir.

Pour the pistachio coating over the cereal. Gently toss or fold until most of the cereal is covered without crushing the Chex.

Add the powdered sugar and toss again until the cereal is well coated. If you're using a paper bag, fold the top closed and shake it until the powdered sugar is evenly distributed.

Spread the puppy chow out and let it cool completely before storing or serving.

Keep leftovers in an airtight container. For the best crunch, I recommend eating it within the first day or two.