Bring a medium saucepan of salted water to boil. Add pasta and cook according to package directions. Reserve pasta water, drain pasta and set aside.
Meanwhile, in a large skillet, heat olive oil over medium heat. Add sliced bacon and cook, stirring until browned, 5 to 8 minutes. Drain off excess fat leaving approx. 2-3 tbsp in pan. Add onions and chili pepper flakes and cook, stirring occasionally, until onions are soft and golden, 5 to 8 minutes. Add garlic and cook until fragrant, about 30 seconds. Add diced tomatoes, crushed tomatoes and tomato paste and cook, stirring until thick, about 2 minutes. Add vodka and cook until sauce has reduced by half, about 10 minutes. Stir in cream and cook until the sauce thickens, about 5 minutes. Stir in basil and remove from heat.
Toss sauce with pasta adding a bit of reserved pasta water to get the desired texture. Season with salt and pepper to taste. Serve immediately garnished with cheese and fresh basil.
Instead of bacon, use pancetta or sausage removed from the casing and crumbled.