In a large mixing bowl, combine turkey, pork, spinach, cheese, egg, basil, parsley, garlic powder, salt, red pepper flakes and 1/2 of the bread crumbs. Using your hands, mix all the ingredients until well incorporated. Use immediately or place in refrigerator for up to 24 hours.
Place the remaining bread crumbs into a small bowl. Using a scale, weigh meatballs into 1.5-ounce portions and place on a sheet pan. Using your hands, shape the meatballs into rounds, roll in the bread crumbs and place on a parchment paper lined baking sheet. Bake for 20 minutes or until golden and cooked through.