Hello deathx,
To complete this level, you just need to keep 16 breads in any of your inventory slot and check /level to complete it, as soon as the level is completed, it takes away the breads from your inventory.
In simple terms, it is asking you to give 16x breads to /level (you need to have green ticks on all the requirements to complete it, just keep 16 breads and 12 haybales in your inventory and then it completes)
Hope this helps!!