In a large saucepan, melt the butter over low heat. Add the marshmallows and stir with a wooden spoon until completely melted. Remove from heat.
Add in the Rice Krispies cereal. Stir until well coated.
Coat a 13x9x2 inch pan with cooking spray. Using wax paper or a buttered spatula, evenly press the mixture into the pan and let cool.
Once completely cooled, use a heart-shaped cookie cutter to cut the treats out and set on a plate.
Using a microwave safe bowl, heat the white chocolate wafers in 30 second increments (stiring each time), until completely melted. If using food color, add now and stir.
Dip half of each heart-shaped treat into the chocolate, and place onto a piece of wax paper to harden, roughly 15 minutes. Place into an airtight container for later or enjoy now!