||Saute pancetta in olive oil in a 12" skillet over moderate heat and cook until it begins to crisp, 3-5 minutes.
||Add onion and saute until softened.
||Add garlic and saute for 1 minute.
||Add bell pepper, broth and cream and bring to a simmer for about 5 minutes.
||Puree sauce in a food processor until almost smooth (a little texture is nice). Return to skillet and season with salt and cayenne to taste. Just before pasta is ready, reheat gently.
||Cook pasta according to directions, drain and reserve some of the water.
||Toss pasta with sauce, add 1/2 c of parmesan and toss again.
||Add as much of reserved pasta water as needed to help sauce coat noodles nicely.
||Serve immediately and top each serving with some of the remaining parmesan cheese and parsley.