Try making a separate diluted bottle of cereal flavoring, say at 20%. And use it out of that diluted bottle.
Otherwise ONE drop of it is sufficient. Maybe even less...a micro drop or toothpick smear. Cereal flavoring is strong, and salty.
Maybe try some vanilla in your recipe? Food marshmallows have vanilla in them. Marshmallow flavoring I doubt does. Just a thought. Vanilla Swirl might be good to use in it. IDK.
I can't try mixing anything atm

all of my DIY goodies are packed up getting ready to begin remodel work in our house again.
ETA: When I say ONE drop, I suggest one drop per 7 or 10ml.
Trying a separate
diluted bottle of the cereal, you could maybe use it in smaller size (3ml, 5ml). IDK, I have not tested it to see yet. Just thinking out loud.
