01 - Place the rice cereal squares in a large mixing bowl, ensuring there's ample room for coating.
02 - In a microwave-safe bowl, combine white chocolate chips, peanut butter, and butter. Microwave in 30-second intervals, stirring between each, until smooth and fully melted (about 1-2 minutes). Stir in vanilla extract until well incorporated.
03 - Pour the melted chocolate mixture over the cereal. Using a spatula, gently fold and toss the cereal until every piece is evenly coated with the chocolate mixture.
04 - Transfer the chocolate-coated cereal to a large gallon-size zip-top bag. Add the powdered sugar, seal the bag tightly, and shake vigorously until all cereal pieces are thoroughly coated in white powder.
05 - Spread the coated cereal evenly on a parchment-lined baking sheet. Allow to cool and set for 10 minutes, ensuring the chocolate coating firms up slightly.
06 - Once cooled, add green candy-coated chocolates, mini marshmallows, gold chocolate coins, and green sprinkles. Gently toss everything together until evenly distributed.
07 - Transfer the completed St. Patrick's Day Lucky Chow to an airtight container. Store at room temperature until ready to serve. Best enjoyed within 3 days for optimal freshness and texture.