In a medium bowl, mix ground turkey, egg, breadcrumbs, Parmesan cheese, marinara sauce, spinach, parsley, basil, garlic, salt, and pepper.
Using damp hands, form turkey mixture into meatballs that are about 2 tablespoons each.
Spray a large stockpot with cooking spray and set to medium-high heat. Add in meatballs and brown on all sides, approximately 2 minutes on each side. Transfer meatballs to a bowl and set aside.