For the meatballs: In a large bowl, mix together the lamb, couscous, scallions, garlic, egg, parsley, olive oil, mint, oregano, salt, cumin, cinnamon, and cayenne pepper. Form the mixture into 15 to 16 (2-inch diameter) meatballs.
For the sauce: Heat the oil in a large nonstick skillet over medium-high heat. Add the meatballs and cook until brown on all sides, about 6 minutes. Add the marinara sauce, cinnamon sticks, and ground cinnamon. Bring the sauce to a boil and reduce the heat to a simmer. Cook, turning occasionally, until the meatballs are cooked through, 10 to 12 minutes. Discard the cinnamon sticks. Transfer the meatballs and sauce to a large bowl and serve.
To make 1 cup cooked couscous, bring 1/2 cup water or stock to a boil. Add 1/3 cup uncooked couscous and cover the pan. Remove the pan from the heat and allow the mixture to sit for 5 minutes until all the liquid has been absorbed. Fluff with a fork and allow to cool.