Preheat your oven to 400°F.

In a large mixing bowl, combine the ground chicken, ricotta cheese, Parmesan cheese, breadcrumbs, parsley, egg, garlic, salt, black pepper, oregano, and red pepper flakes. Mix until well combined, but do not overmix.

Using your hands, form the mixture into meatballs, about 1.5 inches in diameter. You should get around 20 meatballs.

In a large oven-safe skillet, heat a tablespoon of olive oil over medium heat. Add the meatballs in batches, cooking until browned on all sides, about 5 minutes. Transfer the browned meatballs to a plate.

Once all the meatballs are browned, return them to the skillet and pour the marinara sauce over the top. Bring to a simmer, then transfer the skillet to the preheated oven.

Bake for 15-20 minutes, or until the meatballs are cooked through and reach an internal temperature of 165°F.

Serve the meatballs hot, garnished with additional parsley and Parmesan cheese if desired.