Step 1:
Preheat your oven to 400°F.
Spray or lightly oil a 9×13 casserole dish.

Step 2:
Slice the chicken breasts horizontally to create thinner fillets.
Lay them in a single layer in the prepared casserole dish.

Step 3:
Season the chicken with salt, black pepper, and rub with 2 minced garlic cloves for extra flavor.

Step 4:
In a medium bowl, mix together the softened cream cheese, heavy cream, chopped spinach, remaining 2 minced garlic cloves, salt, black pepper, Italian seasoning, smoked paprika, onion powder, and chili powder.

Step 5:
Stir in the Parmesan cheese and ½ cup of the shredded mozzarella.
Mix well until the mixture is creamy and combined.

Step 6:
Spread the creamy spinach mixture evenly over the chicken breasts.

Step 7:
Top with chopped sun-dried tomatoes.
Drizzle with 1 tablespoon of reserved oil from the sun-dried tomato jar for extra flavor.

Step 8:
Sprinkle the remaining ¼ cup of mozzarella cheese over the top.

Step 9:
Cover the casserole dish with foil and bake for 20 minutes.

Step 10:
Remove the foil and bake uncovered for another 15 minutes, until the chicken is cooked through (internal temperature of 165°F) and the cheese is golden and bubbly.

Step 11:
Sprinkle fresh chopped parsley over the dish before serving.