In a large mixing bowl, pour 12 cups of Marshmallow Fruity PEBBLES cereal, combine with 3 cups of mini marshmallows mix and set aside.
In a large saucepan, melt 1 stick of butter.
Once butter is melted, slowly add in the remaining bags of marshmallows and mix until smooth.
Pour the melted butter and marshmallow mixture into the bowl of Marshmallow Fruity PEBBLES cereal a little bit at a time, mixing until cereal is coated evenly.
Line 2 cookie sheets with buttered wax paper.
Scoop the mixture onto the cookie sheets and spread out until even using damp hands.
Allow the mixture to harden for about 1-2 hours.
Cut the mixture using a greased heart-shaped cookie cutter and place the heart-shaped bars onto wax paper
Serve and enjoy! Keep bars in a sealed container to store.