Bring a large pot of heavily salted water to a boil. Add pasta and cook according to package directions for al dente. Reserve 1 cup of pasta water, then drain the pasta.

While pasta cooks, heat olive oil in a large skillet over medium-high heat. Add onion and cook until soft, about 3-4 minutes. Add garlic and cook for 1 minute until fragrant. Add the ground turkey, break it apart with a spoon, and cook until browned, about 5-7 minutes. Drain any excess fat.

Stir in the Italian seasoning, red pepper flakes, salt, and pepper. Cook for 30 seconds until fragrant. Pour in the crushed tomatoes, stir to combine, and bring to a simmer. Reduce heat to low, cover, and let simmer for at least 10 minutes.

Add the drained pasta to the skillet with the sauce. Toss to coat, adding reserved pasta water (starting with 1/4 cup) to help the sauce cling to the pasta. Serve immediately, garnished with Parmesan cheese and fresh parsley or basil.