Preheat your oven to 425 degrees F. Line 2 large rimmed sheet pans with parchment or foil. Divide the zucchini slices between both pans so they are in a single layer with a little breathing room. Crowding them causes steaming instead of roasting, and you will lose that golden-edge flavor.

Drizzle 2 tablespoons of the olive oil over the zucchini, sprinkle with 1/2 teaspoon of the salt and the black pepper, and toss directly on the pans. Spread back into a single layer. Roast for 15 to 18 minutes, flipping once halfway through, until the edges are golden and the centers are tender.

While the zucchini roasts, bring a large pot of well-salted water to a boil. Cook the pasta according to the package directions until just al dente. Before you drain it, scoop out at least 1/4 cup of the starchy pasta water and set it aside. Drain the pasta.

If you would like toasted pine nuts on top, add them to a small dry skillet over medium heat. Stir them every 30 seconds for about 2 to 3 minutes until they smell nutty and turn light golden. Watch them closely because they burn fast. Transfer to a plate immediately.

Add the pesto and the remaining 1 tablespoon of olive oil to the large serving bowl or back into the empty pasta pot. Stir in the reserved pasta water, one tablespoon at a time, until the pesto loosens into a saucy consistency.

Add the drained pasta to the pesto and toss to coat. Gently fold in the roasted zucchini. Taste and add the remaining 1/4 teaspoon salt if needed. Serve in bowls topped with pine nuts and a generous handful of grated Parmesan.