01 - Place rice cereal squares in a large mixing bowl.
02 - Combine white chocolate chips, peanut butter, and butter in microwave-safe bowl. Microwave in 30-second intervals, stirring between each, until smooth and fully melted (approximately 1-2 minutes).
03 - Stir vanilla extract into melted chocolate mixture until well incorporated.
04 - Pour chocolate mixture over cereal. Gently fold with spatula until all pieces are evenly coated.
05 - Transfer coated cereal to gallon-size zip-top bag. Add powdered sugar, seal bag, and shake vigorously until cereal is thoroughly coated in sugar.
06 - Spread mixture onto parchment-lined baking sheet. Allow to cool for 10 minutes until chocolate sets.
07 - Add green candy-coated chocolates, mini marshmallows, gold chocolate coins, and green sprinkles to cooled cereal. Gently toss until evenly distributed.
08 - Transfer to airtight container. Store at room temperature until ready to serve.