Add all of the Chex cereal to a large mixing bowl
Add the chocolate chips, peanut butter, and butter to a microwave-safe bowl and microwave for 30 seconds. Stir very well until it’s all melted and smooth. If you need to heat it more, do so in 20-second increments, stirring well in between.
Pour the melted chocolate over the Chex cereal and toss it incredibly well until every Chex piece is covered in the chocolate.
Add the powdered sugar and toss it all together until the powdered sugar coats all of the pieces. If you’d like to add more powdered sugar, go for it! I find that 180g is perfect.
Place parchment paper on a flat surface and spread the puppy chow on top of the parchment so that they aren’t overlapping too much.
Allow the puppy chow to dry/solidify a bit (5-8 minutes) before scooping it into your mason jars.