01 - Preheat your oven to 400°F (200°C). Lightly grease a large baking dish, approximately 9x13 inches (23x33 cm).
02 - In a large pot, boil salted water and cook the pasta until just al dente. Drain thoroughly and set aside.
03 - Melt 2 tablespoons of unsalted butter in a large skillet over medium heat. Add the diced onion, celery, and carrots. Sauté for 5 minutes until the vegetables begin to soften.
04 - Add the minced garlic, chopped sage, thyme, dried rosemary, salt, and pepper to the skillet. Cook for an additional 1 minute until fragrant.
05 - Introduce the Italian sausage to the skillet. Break up the meat with a spoon and cook until thoroughly browned, approximately 5-7 minutes.
06 - If using, pour the dry white wine into the skillet to deglaze, scraping any browned bits from the bottom. Let it simmer until nearly evaporated, about 2 minutes.
07 - Stir in the chicken or vegetable broth and heavy cream. Allow the mixture to simmer gently for 3-4 minutes, enabling the flavors to meld.
08 - Add the cooked pasta, shredded mozzarella cheese, and half of the grated Parmesan cheese to the skillet. Toss everything together to ensure even distribution. Transfer this mixture to the prepared baking dish.
09 - In a small bowl, combine the fresh breadcrumbs with the melted butter and chopped fresh parsley. Sprinkle this mixture evenly over the top of the pasta bake.
10 - Evenly distribute the remaining grated Parmesan cheese over the breadcrumb topping. Bake the casserole uncovered for 20-25 minutes, or until the top is golden brown and the filling is bubbling.
11 - Allow the pasta bake to rest for 5 minutes before serving.