01 -
Preheat the oven to 400°F (204°C) and lightly grease a 9×13 inch (23×33 cm) baking dish with butter or cooking spray. Set aside.
02 -
Cut the chicken breasts in half horizontally to form four cutlets. Even out thickness by gently pounding with a rolling pin.
03 -
In a large bowl, whisk 1 tablespoon olive oil with minced garlic, Italian seasoning, salt, and black pepper. Add the chicken cutlets, toss to coat, cover, and refrigerate for 15 to 30 minutes.
04 -
Heat the remaining 1 tablespoon olive oil in a large skillet over medium heat. Add spinach and cook, stirring frequently, until wilted, about 2 to 3 minutes. Remove from heat and set aside.
05 -
In a medium bowl, beat the softened cream cheese until smooth. Add wilted spinach, 1/2 cup shredded mozzarella, and Parmesan if using. Mix thoroughly until well combined.
06 -
Remove chicken from marinade and let excess drip off. Optionally, sear chicken in skillet for 1 to 2 minutes per side for added flavor. Arrange cutlets in a single layer in the prepared baking dish.
07 -
Spread the spinach and cream cheese mixture evenly over the chicken. Sprinkle remaining 1/2 cup mozzarella cheese over the top.
08 -
Bake for 20 to 30 minutes until the chicken is fully cooked and the cheese is melted and lightly golden. Remove from oven and let stand for 5 minutes before serving.