Preheat oven to 400°F.
Place bread cubes into a food processor. Pulse into small bits then place crumbs into a medium sized mixing bowl.
In a small bowl, mix the olive oil with the grated garlic, poultry seasoning, salt and pepper. Pour the mixture over the breadcrumbs and toss to coat. Pour the breadcrumbs out onto the parchment-lined sheet tray and bake for 12 minutes or until brown.
Bring a large pot of salted water to a boil then drop the pasta into the water and cook to al dente. Before draining, reserve 1/4 cup of the starchy cooking water for the sauce.
Heat the olive oil in a large skillet over high heat. Once hot, add the sausage and cook, breaking it up with the back of spoon. Once brown, remove sausage and wipe out pan.
Place the pan back on top the heat and add 2 tablespoons of butter. Once the butter is hot, add the mushrooms and cook, stirring occasionally, until brown. Once brown, add the onions, carrot and celery, and cook until softened, about 8 minutes. Add the sage and thyme, and season with salt and black pepper. Add the sausage back into the sauce. Once herbs become fragrant, add in the heavy cream, the reserved starchy pasta water and the parmesan cheese. Bring the sauce to a bubble and stir in the chopped parsley.
Toss the pasta with the warm sauce and serve with Stuffing Breadcrumb Topping.