Preheat the oven to 400°F (200°C).

On a baking sheet, toss the cherry tomatoes and unpeeled garlic with olive oil, salt, and pepper.

Roast in the oven for 25-30 minutes until tomatoes are blistered and garlic is soft.

While the tomatoes are roasting, bring a large pot of salted water to a boil.

Add the spaghetti and cook according to package instructions until al dente.

Reserve 1 cup of pasta water, then drain the pasta in a colander.

In a mixing bowl, squeeze the roasted garlic out of its skins and mash it.

Add the roasted tomatoes and basil to the bowl, mixing well.

Combine the pasta with the tomato mixture, adding reserved pasta water as needed to create a sauce.

Serve hot, topped with grated parmesan cheese and red pepper flakes if desired.