Cook pasta according to instructions on box. Reserve 1/4 cup of pasta water, drain, and set aside.

Add basil, pepper, 4 tbsp olive oil, garlic, salt, and breadcrumbs to the bowl of a food processor and pulse to combine. Add balsamic vinegar and puree until smooth.

Turn on your oven's broiler.

In a large ovenproof sauté pan, heat 1 tsp olive oil. Cook cherry tomatoes, seasoning with salt and pepper, over medium high heat for approximately 1 minutes. Add pasta to the pan along with the pesto sauce and 2 Tbsp of the reserved pasta water. Stir together until everything is combined. Add more pasta water if necessary to thin the mixture out. Cook for approximately 30 seconds and top with mozzarella.

Add skillet to the oven and broil until cheese is melted. Serve immediately.