01 - Line a 9x13-inch baking pan with parchment paper or lightly grease the surface to prevent sticking.
02 - Place the Rice Krispies cereal in a large mixing bowl, ensuring enough space for coating later.
03 - Combine chocolate chips, peanut butter, and butter in a microwave-safe bowl. Microwave in 30-second intervals, stirring thoroughly between each interval, until completely melted and smooth, approximately 1–2 minutes total.
04 - Stir the vanilla extract into the melted chocolate mixture until well incorporated.
05 - Pour the warm chocolate-peanut butter mixture over the Rice Krispies. Gently fold with a spatula until all cereal pieces are evenly coated without crushing them.
06 - Transfer the coated cereal mixture to the prepared baking pan. Press lightly into an even layer, being careful not to compress the cereal too tightly.
07 - Place powdered sugar in a large zip-top bag. Cut the Rice Krispies mixture into squares, then add pieces to the bag and gently shake until well coated with powdered sugar.
08 - Remove coated squares from the bag and place on a wire rack or parchment-lined tray. Allow to set for 10 minutes before serving.