Bring a large pot of salted water to a rolling boil. Add spaghetti and cook for 8–10 minutes until al dente. Reserve pasta water and drain spaghetti. Toss with olive oil to prevent sticking.

In a large skillet, heat butter and olive oil over medium-low heat. Add minced garlic and sauté for 1–2 minutes until fragrant.

Stir in Italian seasoning and lemon zest, mixing for about 30 seconds until aromatic.

Pour in lemon juice and simmer for 1–2 minutes to allow flavors to incorporate.

Add cooked spaghetti to the skillet and toss gently in the sauce, incorporating reserved pasta water as needed.

Remove from heat and fold in fresh parsley. Season with salt and black pepper.

Transfer pasta to serving plates and garnish with Parmesan cheese and crushed red pepper flakes if desired.