Preheat your oven to 400°F (200°C). Peel, seed, and cube the butternut squash into bite-sized pieces. Drizzle with olive oil, salt, and pepper and toss until even.

Spread the seasoned butternut squash evenly on a baking sheet and roast for 20–25 minutes until tender and caramelized, stirring halfway.

Heat a tablespoon of olive oil in a skillet over medium heat. Add the Italian sausage and cook for 5–7 minutes until browned and cooked through. Remove and set aside.

In the same skillet, add another splash of olive oil if needed, and sauté the diced onion for about 5 minutes until softened. Add minced garlic and cook for 1 minute.

Add baby spinach to the skillet and cook for 2–3 minutes until wilting. Turn off the heat and set aside.

Boil salted water in a large pot and cook pasta according to package directions, typically 8–10 minutes for al dente. Reserve a cup of pasta water before draining.

Once squash is roasted, mix it into the skillet with the sausage, spinach, garlic, and onions. Stir well.

Pour in the heavy cream and mix in reserved pasta water to adjust the sauce consistency. Add sage, salt, pepper, and red pepper flakes to taste.

Add drained pasta to the skillet and toss to coat with the sauce. Simmer on low heat for a minute to meld flavors. Sprinkle with grated Parmesan.

Serve warm, garnished with additional Parmesan and possibly fresh herbs or red pepper flakes.