Place the rice in a fine mesh strainer and rinse with cold water until it runs clear. Drain well and set it aside.
In a medium-sized saucepan, heat the olive oil on medium-high heat. Add the vermicelli and saute, stirring constantly, until golden brown, about 4-5 minutes.
Add the now-drained rice to the pot and saute, stirring constantly, for 5 minutes on medium-low heat until the rice is fully incorporated with vermicelli. Season with kosher salt and cinnamon, if using.
Add the 4 cups of water and bring the mixture to a full boil. Cover and reduce the heat to low.
Continue to simmer without stirring for 15-20 minutes until all the water is absorbed.
Remove from the heat and let it rest, covered, for 5 minutes. Uncover and fluff with a fork.
Taste for seasoning and adjust as necessary. Garnish with black pepper and chopped parsley, if desired.