In a large bowl, combine ground turkey, chopped spinach, breadcrumbs, Parmesan cheese, milk, egg, minced garlic, onion powder, Italian seasoning, salt, and pepper. Mix until well combined.
Preheat your oven to 400°F (200°C).
Form the turkey mixture into meatballs, about 1.5 inches in diameter, and place them on a baking sheet lined with parchment paper.
Bake the meatballs in the preheated oven for 20 minutes or until cooked through and golden brown.
While the meatballs are baking, heat olive oil in a large skillet over medium heat. Add heavy cream, chicken broth, and red pepper flakes (if using) to the skillet. Bring to a simmer.
Once the meatballs are done, transfer them to the skillet with the creamy sauce. Gently stir to coat the meatballs in the sauce and let simmer for an additional 5 minutes.
Serve the meatballs warm, garnished with fresh parsley.