Preheat toaster oven to 400°F. Toss together tomatoes, garlic, pepper, 3 tablespoons of the oil, and 1/2 teaspoon of the salt on a small baking sheet lined with aluminum foil. Place in preheated toaster oven, and cook until tomatoes burst and char slightly, about 20 minutes. Meanwhile, prepare penne in microwave according to package directions; set aside.

Whisk together balsamic vinegar, remaining 3 tablespoons oil, and remaining 1/2 teaspoon salt in a large bowl. Add roasted tomato mixture, cooked penne, chopped salami, and arugula, and toss gently to coat. Arrange penne mixture on a large serving platter, and top with torn mozzarella and basil.