Preheat your oven to 375°F (190°C). Grease a baking dish with a bit of olive oil.
In a large skillet, heat 2 tablespoons of olive oil over medium heat. Season the chicken breasts with salt and pepper, then add them to the skillet. Sear the chicken for about 5-7 minutes on each side until golden brown. Remove the chicken from the skillet and set aside.
In the same skillet, add minced garlic and sauté until fragrant (about 1-2 minutes).
In a medium bowl, mix together the cream cheese, sour cream, chopped artichoke hearts, thawed spinach, mozzarella, Parmesan, onion powder, and Italian seasoning. Stir until well combined.
Place the seared chicken in the greased baking dish. Spoon the creamy spinach and artichoke mixture generously over each chicken breast.
Bake in the preheated oven for 25-30 minutes, or until the chicken is cooked through and no longer pink in the center (internal temperature should reach 165°F/75°C).
Optional: In the last 5 minutes of baking, broil the dish on high for a few minutes to achieve a bubbly, golden top. Watch carefully to avoid burning.
Once done, remove from the oven and let it sit for a few minutes. Garnish with chopped parsley before serving.