Cookie

Cookies are food items that are easily obtainable, but do not restore a lot of hunger or saturation.

Trading
Villager farmers will trade 6–10 cookies for 1 emerald as part of their tier 4 trades.

Farmer villagers sell 18 cookies for 3 emeralds as part of their third tier trades.

Food
Cookies can be eaten to restore and 0.4 saturation.

Parrots
Feeding a cookie to a parrot will instantly kill the parrot, and cause it to give off Poison particles as it dies due to chocolate being toxic to parrots. $$, feeding parrots with cookies will inflict the parrot with fatal poison for 1,000 seconds.

Composting
Placing a cookie into a composter has an 85% chance of raising the compost level by 1.