Do you love Rice Krispies treat bars and Lucky Charms cereal? Then this recipe is for you. It's a perfectly festive way to celebrate St. Patrick's day without breaking out any green food coloring. Plus, it only requires three ingredients (and two optional, but highly recommended, ones). These bars have a double dose of marshmallows, thanks to the Lucky Charms, and are an amazingly tasty upgrade to the classic marshmallow and cereal bar.