In a small saucepan, combine the olive oil, whole garlic cloves, and crushed red pepper flakes and warm over medium-low heat for 10 to 15 minutes, swirling occasionally, until the garlic sizzles and turns golden. Remove from heat and let the oil continue to infuse; discard the garlic before tossing.
Bring a large pot of water to a boil and salt it liberally. Add the spaghetti and cook until al dente, about 7 to 8 minutes, then reserve 1/2 cup of the cooking water and drain the pasta.
Return the drained pasta to the pot and drizzle in the garlic-infused oil, discarding the garlic cloves if you haven't already. Toss to coat the spaghetti evenly.
Add the chopped parsley, lemon zest, and grated Vegetarian Parmesan. Season with a sprinkle of salt and several grinds of black pepper, then toss to combine.
If the pasta seems dry after adding the cheese, add the reserved cooking water 1 tablespoon at a time, tossing until the sauce lightly coats the spaghetti and it glistens without dripping with oil.
Serve immediately with additional grated Parmesan if desired.
