Combine the ground turkey, breadcrumbs, egg, minced garlic, oregano, salt, and black pepper in a mixing bowl. Mix gently until the ingredients are evenly distributed.
Shape the mixture into 16 meatballs of similar size. Set them aside on a plate.
Heat the olive oil in a large skillet over medium heat. Add the meatballs and cook for 8 to 10 minutes, turning them until browned on all sides.
Pour the marinara sauce into the skillet. Lower the heat and let the meatballs simmer in the sauce for 10 minutes until cooked through.
While the meatballs simmer, spiralize the zucchinis into noodles. Place the noodles in a serving bowl without cooking them to keep their texture fresh.
Spoon the meatballs and sauce over the zucchini noodles. Top with grated Parmesan and fresh basil leaves before serving.