Boil a large pot of salted water and cook the rigatoni according to the package instructions. Drain thoroughly and set aside in the pot.
While the pasta cooks, melt the butter in a large saucepan over medium heat. Add the sliced shallots and sauté for 2-3 minutes, or until they turn translucent. Stir in the minced garlic and cook for an additional minute.
Pour in the half-and-half, stirring to deglaze the pan and incorporate any onions or garlic. Add the grated Parmesan cheese and cream cheese cubes, stirring frequently for 2-3 minutes until the cream cheese melts. Stir in the roasted red peppers and warm through.
Carefully transfer the sauce to a food processor or blender, and puree until smooth and creamy. Adjust seasoning with salt and pepper to taste.
Pour the blended sauce over the cooked pasta and toss gently to coat evenly.
Serve hot, garnished with fresh basil and additional Parmesan cheese. Enjoy!