Forgive the poor attempt at wordplay, but mallo-palm is the ideal replacement for napalm.
The marshmallows are superheated to turn them into a boiling, bubbling liquid, which can then be used to spray from a plane, or a handheld device (a heavily modified flamethrower) at the enemy (i know napalm wasn't designed to be sprayed at troops, but this is).
This has many benefits over current weaponary
a) It would be alot cheaper to manufacture (could be bought in bulk from the local supermarket).
b) It would be very effective against troops, as the gooey consistency would cause the heated mallow to stick to the skin.
c) No damage to buildings, as there is no risk of the marshmallow spreading (unlike fire).
d) After it cooled, it could be eaten, both by hungry refugees and troops.
... Many more
As a slight variation, mini marshmallows could be fired from a rifle for assasinations.
Our enemies will fear us!

Inspired by [farmerjohn]'s mallows from space...

*edit*
Have just discovered the edible non-lethal force idea...
Quite similar, but this is edible lethal force.