1. Prepare Oven and Dish:

• Preheat the oven to 400°F (200°C).
• Prepare a 9×13 inch casserole dish by spraying it with cooking spray or lightly coating it with oil.

2. Prepare and Season Chicken:

• Slice the chicken breasts horizontally through the middle to create four thinner cutlets. (Alternatively, pound the whole breasts to an even thickness).
• Place the chicken cutlets in the prepared casserole dish in a single layer.
• Season the chicken generously with salt and black pepper on both sides.
• Rub 2 of the minced garlic cloves over the chicken breasts.

3. Make the Creamy Topping:

• In a medium bowl, combine the softened cream cheese and heavy cream. Stir until mostly smooth.
• Add the chopped spinach (if using frozen, ensure it’s thawed and squeezed very dry).
• Add the remaining 2 minced garlic cloves, 1/4 tsp salt, 1/4 tsp black pepper, Italian seasoning, smoked paprika, onion powder, and chili powder. Stir well to combine all seasonings into the cream cheese mixture.
• Stir in the grated Parmesan cheese and half (1/2 cup) of the shredded mozzarella cheese. Mix well.

4. Assemble the Dish:

• Spread the creamy spinach-cheese mixture evenly over the top of the chicken breasts in the dish, covering them completely.
• Scatter the chopped, drained sun-dried tomatoes over the cream cheese layer.
• Drizzle the reserved 1 tablespoon of oil from the sun-dried tomato jar over the tomatoes and chicken.
• Top evenly with the remaining 1/4 cup of shredded mozzarella cheese.

5. Bake Covered:

• Cover the casserole dish tightly with aluminum foil.
• Place the dish in the preheated oven and bake for 20 minutes.

6. Bake Uncovered:

• Carefully remove the aluminum foil.
• Return the dish to the oven and bake uncovered for another 15 minutes, or until the chicken is fully cooked through (internal temperature reaches 165°F/74°C) and the cheese is melted and bubbly, possibly starting to brown slightly.

7. Garnish and Serve:

• Let the chicken rest for a few minutes after removing it from the oven.
• Sprinkle with fresh chopped parsley just before serving.
• Serve warm, spooning some of the pan sauce over the chicken if desired.