Cook pancetta in olive oil over medium-low heat in a large skillet, stirring occasionally, until crispy.
Remove pancetta with a slotted spoon to a bowl, leaving rendered fat in the pan.
Add butter to the skillet and stir in shallots, garlic, and red pepper flakes.
Cook, stirring occasionally, until shallots are soft and garlic is fragrant, about 3-4 minutes.
Stir in tomato paste and cook 3-4 minutes until darkened to brick color.
Add red wine and scrape up browned bits with a wooden spoon.
Simmer for about 5 minutes to cook off alcohol.
Stir in crushed tomatoes, most of the pancetta, and basil leaves.
Season with salt and pepper and bring to a gentle simmer for about 15 minutes.
While sauce reduces, bring a pot of salted water to a boil and cook pasta 2-3 minutes less than box instructions.
Reserve 3/4 cup pasta water and drain pasta.
Stir cream into the tomato sauce until incorporated.
Add pasta water and drained pasta to the sauce.
Simmer 4-5 minutes until sauce clings to pasta.
Season to taste with salt and pepper.
Spoon into bowls and top with parmesan, reserved pancetta, and torn basil.