Prepare your workspace by clearing your kitchen counter and gathering all your ingredients and equipment.

In a microwave-safe bowl, combine the semisweet chocolate chips and creamy peanut butter. Microwave for 30 seconds, stir, and continue heating in 15-second intervals until fully melted.

Once melted, mix in the butter and vanilla extract until smooth.

In a large mixing bowl, add the Rice Chex cereal and pour the chocolate-peanut butter mixture over the cereal, gently folding until every piece is evenly coated.

Transfer the coated cereal to a large plastic storage bag or container. Add the powdered sugar and shake well until all pieces are coated.

Spread the coated cereal on a baking sheet lined with parchment paper and allow it to cool for about 10 minutes.

Once cooled, enjoy your Puppy Chow Chex Mix immediately or store it in an airtight container.