Cover a tray with parchment paper or foil (in this case we must grease a little before starting making chocolate cereal and marshmallow hearts recipe).
Heat the butter in a pot, add marshmallows, and mix until everything is melted. Be careful not to burn the mixture.
Add the red food color as you like.
Stir in three chocolate cereal cups, mixing constantly until combined.
Mixing would be very hot. Carefully pour the mix into the tray and press with your wet hands or extend with a baking spoon. Spread mix until it measures about an inch high.
Let it cool down. After a few minutes, it will get hard. Cut with the heart-shaped cookie cutters.
Serve the treats into a plate and get ready to enjoy them or give them as Valentine's treat for your friends.