01 - Place rice Chex cereal in a large mixing bowl and set aside for coating.
02 - Combine chocolate chips, peanut butter, and butter in a microwave-safe bowl. Microwave in 30-second intervals, stirring between each, until completely melted and smooth, approximately 1-2 minutes total.
03 - Stir vanilla extract into the melted chocolate mixture until fully incorporated.
04 - Pour the melted chocolate mixture over the cereal. Gently fold with a rubber spatula until all cereal pieces are evenly coated.
05 - Transfer the coated cereal to a large zip-top bag. Add powdered sugar, seal the bag, and shake vigorously until all pieces are thoroughly coated with sugar.
06 - Melt green candy melts (or white chocolate chips with green food coloring) in a small microwave-safe bowl using 20-second bursts, stirring until smooth.
07 - Drizzle the melted green candy over the puppy chow and toss gently to distribute evenly throughout the mixture.
08 - Spread the mixture on a parchment-lined baking sheet. Sprinkle with green and gold sprinkles and green chocolate candies. Let set for 10 minutes before serving.