Bring a large sauce pan of salted water to boil and cook your spaghetti according to package directions. Reserve ½ cup of pasta water, drain, and set cooked spaghetti aside.
While the pasta is cooking, bring a large saute pan or fry pan to medium heat and add the olive oil, a pinch of salt, red pepper flakes, onions, and peppers and saute for 7-8 minutes until the peppers are just tender. Then, add the sliced zucchinis and cook for additional 3-4 minutes until the zucchini is tender.
Next, add the tomato paste and white wine to deglaze the pan, scraping any brown bits off the bottom. Add the reserved pasta water, heavy cream, and cooked spaghetti. Season with another pinch of salt. Stir until the sauce thickens and coats the pasta, about 2-3 minutes.
To finish, turn off the heat and stir in the parmesan cheese. Taste and adjust for salt. Serve with some fresh parsley.