Various designs are available, eg:

http://www.guinnessworldrecords.com/news/2018/1/how-to-make-your-own-marshmallow-catapult-and-potentially-become-a-record-breaker-508784

This one requires gluing (and therefore needs time for the glue to harden). Uses several ice block sticks, a bulldog clip and milk bottle cap.

https://www.wikihow.com/Make-a-Marshmallow-Catapult

This one has 3 different designs, the simplest using only 7 skewers, 4 marshmallows (plus one for a projectile), a plastic spoon and some masking tape

https://www.diynetwork.com/how-to/make-and-decorate/crafts/how-to-make-a-toy-marshmallow-catapult

This one uses no glue, but tongue depressors rather than ice block sticks, held together with rubber bands

Type

Duration

# Deliveries

Duration

Simplest version (using bamboo skewers) For each participant:

• 6 bamboo skewers
• 5 marshmallows
• 1 rubber band
• 1 plastic spoon
• masking tape (a few cm)

• masking tape
• target (bucket, shallow container or painted on cardboard)