Heat the olive oil in a large pan over medium heat. Add the onion, cinnamon stick, and bay leaf and saute until the onion is translucent, about 5 minutes. Add the farro, stir to coat with the olive oil, and toast for 2 minutes. Then, add 8 cups of water and the salt. Bring to a boil, then turn down the heat and simmer for 30 minutes, or until the farro is tender.
Drain the farro and discard the cinnamon stick and bay leaf. Add the butter and the parsley to the hot farro and stir until the butter is melted and the parsley is fully mixed in. Serve warm.