Bring a large pot of salted water to boil, steaming zucchini strips in a colander or steaming basket over water until tender but still slightly crunchy. Rinse with cold water to stop them cooking.
After zucchini is cooked, set aside and use boiling water to cook the pasta until just al dente.
In the meantime, heat the olive oil in a small skillet over low heat until shimmering. Add red pepper flakes and garlic and cook briefly until the garlic is fragrant and soft but not browned, 2-3 minutes. Turn off the heat. Reserve 1 cup of pasta water before draining pasta, then return noodles to the pot.
Add garlic mixture, zucchini, Parmesan, and basil. Toss well to combine, adding pasta water as needed to create a creamy sauce. Season to taste with salt and pepper. Serve with more grated Parmesan.