Bring a large pot of salted water to a boil over high heat. Carefully add 1 pound of rigatoni pasta, cooking for about 10-12 minutes or until al dente. Reserve 1 cup of the starchy pasta water before draining the pasta in a colander.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add 3 cups of diced butternut squash and 1 diced red onion, stirring occasionally for 8-10 minutes, until the squash is tender and the onions are translucent.

Push the sautéed vegetables to one side of the skillet. Add 1 pound of spicy Italian sausage, breaking it up with a wooden spoon. Cook for about 5-7 minutes, until browned and cooked through.

Incorporate 4 minced cloves of garlic, 1 bunch of chopped Swiss chard, and 0.5 teaspoon of red chili flakes. Stir together and cook for an additional 2 minutes.

Pour the reserved pasta water into the skillet, scraping any browned bits. Mix in 0.5 cup of creme fraiche and 0.5 cup of grated Parmesan cheese until creamy.

Toss the drained rigatoni into the skillet, mixing with the sauce until completely coated. Heat through for about 1-2 minutes, then serve hot, topped with additional grated Parmesan cheese.