Preheat your oven to 400°F (200°C) and grease a 9x13-inch baking dish.

Slice the chicken breasts horizontally to create evenly thick cutlets and pound them to about ½ inch thick.

In a bowl, combine olive oil, minced garlic, Italian seasoning, salt, and pepper. Marinate the sliced chicken for 15–30 minutes.

Heat a skillet over medium heat, add remaining olive oil, and sauté the spinach for 2–3 minutes until wilted.

In a mixing bowl, beat the cream cheese until smooth, then fold in sautéed spinach and half of the mozzarella cheese.

Arrange the marinated chicken cutlets in the baking dish, spread the creamy spinach mixture over the chicken, and sprinkle remaining mozzarella on top.

Bake for 20–30 minutes until chicken reaches 165°F and cheese is golden and bubbly.

Let the casserole rest for about 5 minutes before serving.