Preheat the oven. Set it to 425°F (220°C). Line a rimmed baking sheet with parchment for easy cleanup.
Prep the tomatoes. Spread cherry tomatoes on the sheet.
Add sliced garlic, olive oil, red pepper flakes, 1 teaspoon salt, and several grinds of pepper. If your tomatoes are very tart, sprinkle on the sugar or honey. Toss to coat and spread in a single layer.
Roast until jammy. Bake 18–22 minutes, stirring once.
You want the tomatoes to burst and release juices, with lightly caramelized edges. Don’t let the garlic burn.
Cook the pasta. While tomatoes roast, bring a large pot of salted water to a rolling boil. Cook pasta until just shy of al dente. Reserve 1 cup of pasta water, then drain.
Combine and build the sauce. Transfer roasted tomatoes and all their juices to a large skillet or the pasta pot.
Add the hot pasta, half the Parmesan, lemon zest, and a splash (about 1/3 cup) of pasta water.
Toss and adjust. Cook over low heat, tossing until the sauce looks glossy and clings to the pasta, 1–2 minutes. Add more pasta water as needed. Season with salt, pepper, and 1–2 teaspoons lemon juice to brighten.
Finish and serve. Fold in basil and a final drizzle of olive oil.
Top with the remaining Parmesan. Serve right away.