Preheat your oven to 375°F (190°C) to ensure even cooking.
Using a sharp knife, carefully cut a pocket into each chicken breast without cutting through.
In a bowl, combine sliced sun-dried tomatoes, fresh spinach, and mozzarella cheese. Mix well.
Stuff each chicken breast pocket generously with the mixture. Secure with toothpicks if necessary.
Sprinkle chicken breasts with salt, pepper, and 1 tablespoon Italian seasoning.
Heat 1 tablespoon olive oil in a large oven-safe skillet over medium-high heat. Sear the stuffed chicken breasts for 3-4 minutes per side until golden brown.
Remove chicken from skillet and set aside. In the same skillet, add remaining olive oil, garlic powder, chicken broth, and heavy cream. Stir and bring to a simmer.
Stir in grated parmesan cheese and additional teaspoon of Italian seasoning until cheese melts and sauce is creamy.
Return stuffed chicken breasts to skillet, spoon some sauce over the top.
Transfer skillet to preheated oven and bake for 20-25 minutes until chicken reaches 165°F (75°C) internal temperature.
Remove from oven and let rest for a few minutes. Serve with creamy sauce drizzled on top and enjoy!