Bring a large pot of salted water to a boil. Add the rigatoni and cook according to package directions until al dente. Reserve about 1 cup of pasta water before draining.

While the pasta is cooking, heat the olive oil in a large skillet or Dutch oven over medium-high heat. Add the sausage and cook, breaking it up with a spoon, until browned and cooked through. Remove the sausage from the skillet and set aside, leaving the rendered fat in the pan.

Add the diced onion to the skillet and cook until softened and lightly caramelized, about 5-7 minutes, scraping up any browned bits from the bottom of the pan. Add the minced garlic and cook for another minute until fragrant.

Pour in the red wine (if using) and cook for 1-2 minutes, allowing the alcohol to evaporate.

Stir in the crushed tomatoes, tomato sauce, oregano, basil, and red pepper flakes (if using). Season with salt and pepper to taste. Bring the sauce to a simmer, then reduce the heat to low and cook for at least 15 minutes, or up to an hour, stirring occasionally.

Return the cooked sausage to the sauce and stir to combine. If the sauce is too thick, add a little of the reserved pasta water to thin it out.

Stir in the cooked rigatoni and toss to coat. If using, stir in the heavy cream for extra richness.

Serve immediately, garnished with grated Parmesan cheese and fresh basil leaves.