A fun treat for children is dehydrating mini marshmallows. It’s a lot cheaper than buying the tiny Kraft ones (if you can even find those), in the grocery store (usually find those with hot cocoa mixes, or in the espresso supply area).
Spread a bag of mini marshmallows on a couple of dehydrator trays, separating as much as you can. Some brands are stickier than others. Dry at 135°, checking after two hours. Break up clumps as needed, and rotate the trays so they are evenly dried. You want the marshmallows to be dry on the outside, and preferably dry inside. The drier they are, the longer the storage time. As for how long, this will depend on the humidity in your house while drying. Drying in arid times will be faster than if it is humid. Plan though for 12 hours time, or put them on before bed.
Add to hot cocoa in camp, or add it to trail mix.