Preheat the oven to 400°F (200°C). Line a large rimmed baking sheet with parchment paper for easy cleanup, or lightly oil it for more caramelization.
Spread the cherry tomatoes on the baking sheet in a single layer. Add the sliced garlic. Drizzle with 3 tablespoons of olive oil, 1 teaspoon of kosher salt, black pepper, and crushed red pepper flakes if using. Toss gently until the tomatoes and garlic are evenly coated. If using zucchini, add it now and toss with the tomatoes.
1 1/2 pounds cherry or grape tomatoes, 4 tablespoons extra-virgin olive oil, 4 cloves garlic, 1 1/2 teaspoons kosher salt, 1/2 teaspoon freshly ground black pepper, 1/2 teaspoon crushed red pepper flakes, 1 small zucchini
Roast the tomatoes for 18–22 minutes, stirring once halfway through, until the skins are wrinkled and starting to burst, juices are released onto the pan, and the garlic is fragrant but not burned. During the last 5 minutes of roasting, drizzle with 1–2 tablespoons balsamic vinegar and stir to coat, letting it reduce slightly into a glossy, tangy sauce.
1 1/2 pounds cherry or grape tomatoes, 4 tablespoons extra-virgin olive oil, 4 cloves garlic, 1 tablespoon balsamic vinegar
While the tomatoes roast, bring a large pot of well-salted water to a boil. Add the pasta and cook according to package directions until al dente. Reserve 1–1 1/2 cups of pasta cooking water, then drain the pasta.
12 ounces pasta, 1 cup pasta cooking water, 1 1/2 teaspoons kosher salt
Return the hot drained pasta to the pot (off the heat) or a large serving bowl. Scrape all of the roasted tomatoes, garlic, pan juices, and browned bits into the pasta. Add the remaining 1/2 teaspoon kosher salt (or to taste), the grated Parmesan, and about 1/2 cup of reserved pasta water. Toss until the pasta is coated in a light, glossy sauce, adding more pasta water as needed if it looks dry.
1 1/2 pounds cherry or grape tomatoes, 4 cloves garlic, 12 ounces pasta, 1/2 cup Parmesan or Pecorino Romano, 1 cup pasta cooking water, 1 1/2 teaspoons kosher salt
While the pasta is still hot, gently fold in the fresh mozzarella pieces, basil, and baby spinach if using. The mozzarella should soften and become slightly stretchy, and the spinach will wilt in the residual heat.
8 ounces fresh mozzarella, 1 cup fresh basil leaves, 2 cups fresh baby spinach
Taste and adjust the seasoning. Add a splash more balsamic or a squeeze of lemon juice for brightness, an extra drizzle of olive oil for richness, and more salt, pepper, or red pepper flakes to taste. Stir in chopped olives if making a cherry tomato and olive variation.
4 tablespoons extra-virgin olive oil, 1 1/2 teaspoons kosher salt, 1/2 teaspoon freshly ground black pepper, 1 tablespoon balsamic vinegar, 1/2 teaspoon crushed red pepper flakes, 1/4 cup pitted Kalamata or Castelvetrano olives, lemon juice
Serve the pasta warm, topped with extra grated Parmesan, a few fresh basil leaves, and a light drizzle of good olive oil and freshly ground black pepper if desired.
4 tablespoons extra-virgin olive oil, 1/2 teaspoon freshly ground black pepper, 1/2 cup Parmesan or Pecorino Romano, 1 cup fresh basil leaves