Preheat your oven to 400°F (200°C) and lightly grease a 9×13-inch baking dish.

Slice the chicken breasts horizontally to create thin cutlets and pound them for even thickness.

Whisk together olive oil, minced garlic, Italian seasoning, salt, and black pepper in a bowl. Marinate the chicken for 15–30 minutes.

In a skillet, heat olive oil and sauté spinach until wilted (about 2–3 minutes). Remove from heat.

Beat the cream cheese until smooth, then mix in sautéed spinach and half of the mozzarella cheese.

In the greased baking dish, layer marinated chicken cutlets and spread the cream cheese mixture over them. Top with remaining mozzarella.

Bake in the oven for 20–30 minutes until the chicken reaches 165°F (75°C) and the cheese is melted and bubbly.

Remove from the oven and let it rest for 5 minutes before serving.