In a large microwave-safe bowl, melt margarine and marshmallows in a microwave set on HIGH for 2 minutes, stirring after 1 minute. Stir until mixture is smooth. To create different coloured KELLOGG'S* RICE KRISPIES* hearts, add food colouring to melted marshmallows before adding cereal.
Add KELLOGG'S* RICE KRISPIES* cereal, stirring until well coated. Spread cereal mixture into a 33 x 23 x 5 cm baking pan coated with cooking spray or butter. Allow cereal mixture to cool slightly. Cut into heart shapes using a heart-shaped cookie cutter or knife.
In keeping with good allergy practices, we remind you to be aware of allergens and to check labels on any packaged goods used. This recipe has been tested using Kellogg's* products. Results with other products may vary.