Step 1: Prepare the Oven and Casserole Dish
Preheat your oven to 400°F. Lightly grease a 9×13 casserole dish with cooking spray or a thin layer of oil.

Step 2: Prepare the Chicken
Slice each chicken breast horizontally to create thinner pieces. Place the chicken in the casserole dish, season with salt, black pepper, and rub with half of the minced garlic. Make sure the chicken is well-coated for maximum flavor.

Step 3: Make the Creamy Filling
In a medium bowl, mix the softened cream cheese, heavy cream, chopped spinach, and the remaining minced garlic. Add Italian seasoning, smoked paprika, onion powder, chili powder, and a bit more salt and pepper. Stir in the Parmesan cheese and half of the shredded mozzarella until well combined.

Step 4: Assemble the Dish
Spread the creamy spinach mixture generously over each chicken breast. Scatter the chopped sun-dried tomatoes over the top and drizzle with 1 tablespoon of reserved oil from the tomato jar. Top everything with the remaining mozzarella cheese for a golden, gooey finish.

Step 5: Bake the Chicken
Cover the dish with foil and bake for 20 minutes to keep the chicken moist. Remove the foil and bake uncovered for another 15 minutes, until the cheese is melted and the chicken is fully cooked. Sprinkle with fresh chopped parsley right before serving for a burst of color and flavor.