Cook pasta as per instructions in salty water. Reserve 1/4 cup of pasta water, drain and place on the side.
Cook the pancetta in a pot over low-medium heat, stirring every minute or so to allow for even cooking. Cook until brown and crispy, approx 6-8 minutes. Remove half the pancetta and place on the side for later.
Lower the heat and add garlic, shallot, optional chili flakes and approx 1/4 tsp of salt. Cook until soft and fragrant, but not brown 3-5 minutes.
Add the tomato paste and cook it until it deepens in color. This will take approximately 7-10 minutes.
Add the crushed tomatoes, mix to combine and cover. Simmer on low heat for 10-15 minutes. Mixing midway through.
Remove from the heat add the Parmesan and heavy cream. Mix to combine, salt if needed. When ready to add pasta add a few tbsp of pasta water first to loosen up the sauce. Add the pasta and top with a sprinkle of the reserved pancetta.