01 - Preheat the oven to 400°F. Grease a 9x13-inch baking dish with olive oil or non-stick spray.
02 - Place chicken breasts in the prepared baking dish. Drizzle with 1 tablespoon olive oil, then season evenly with salt, black pepper, and Italian seasoning.
03 - In a medium bowl, combine quartered cherry tomatoes, finely diced red onion, minced garlic, chopped fresh basil, balsamic vinegar, 1 tablespoon olive oil, salt, and pepper. Toss gently until well combined.
04 - Spoon the bruschetta mixture evenly over the seasoned chicken breasts, spreading it out to cover each piece.
05 - Sprinkle shredded mozzarella and grated Parmesan cheeses over the bruschetta layer. In a small bowl, toss breadcrumbs with melted butter, then scatter the buttery crumbs evenly across the top.
06 - Bake for 30 to 35 minutes, until the chicken reaches an internal temperature of 165°F and the topping is golden brown and bubbling.
07 - Remove from the oven and let rest for 5 minutes. Garnish with additional fresh basil before serving.