Preheat your oven to 375°F (190°C) . In a large skillet over medium heat, warm 1 tbsp of olive oil. Add the minced garlic and sauté ~1 minute, just until fragrant. Add the chopped spinach and cook until wilted. Remove from heat and let cool slightly.

In a medium bowl, combine the cooked spinach and garlic with the cream cheese , mozzarella cheese , salt , black pepper , and red pepper flakes (if using). Mix until smooth and well combined.

Place chicken breasts on a cutting board. Using a sharp knife, cut a pocket into the side of each breast (don’t cut all the way through). Spoon the spinach-cheese mixture evenly into each pocket. Secure with toothpicks if needed.

Transfer the stuffed breasts to a baking dish. Drizzle with the remaining olive oil and sprinkle with Italian seasoning. Bake for 25–30 minutes , or until the chicken is cooked through and the juices run clear.

Allow the chicken to rest 5 minutes before slicing. Serve warm with your favorite sides.