In a medium to large saucepan, melt butter over low heat.
Add the marshmallows and stir until completely melted.
Stir in enough food coloring to make the marshmallows very pink.
Remove from heat.
Add Rice Crispies cereal and mini marshmallows
Stir until cereal is well combined.
Prepare a cookie sheet with sides by spraying with cooking spray or coating with butter.
Butter a spoon or your hands or use wax paper to press the mixture into the pan evenly.
Press conversation hearts evenly around the mixture.
After cooling, use heart shape cookie cutters to cut out treats.