Bring a large pot of salted water to a boil. Cook the 12 oz of pasta according to package instructions until al dente. Drain and set aside.
Preheat oven to 400°F (200°C). Toss halved cherry tomatoes with olive oil, salt, black pepper, and garlic powder on a baking sheet. Roast for about 15 minutes until blistered and juicy.
In a large mixing bowl, combine cooked pasta, roasted tomatoes with juices, chopped basil, shredded mozzarella, and grated Parmesan. Fold in shredded cooked chicken if using. Toss gently to combine.
Transfer pasta mixture to a greased baking dish, spreading evenly. Tear burrata into pieces and scatter over the top.
Bake in preheated oven for 20-25 minutes until cheese is bubbly and golden.
Let the pasta rest for a few minutes. Garnish with fresh basil if desired and serve warm.