Preheat oven to 350°F (175°C).

Cut butternut squash lengthwise and remove seeds.

Lightly oil the cut faces of the squash and season with salt and pepper.

Place squash face-down on a baking sheet and roast for about 45-60 minutes, or until soft.

Remove squash from oven and let it cool slightly.

Scrape the roasted butternut squash meat into a bowl.

Add mascarpone and grated parmesan cheese to the bowl with the squash.

Mix well, adjusting the amount of cheese to taste.

Season the filling with salt and pepper.

For the Gorgonzola Cream Sauce: Combine heavy cream, gorgonzola cheese, and a scrape of nutmeg in a saucepan.

Simmer over low heat for 5-10 minutes, or until the gorgonzola is melted and the sauce has thickened slightly.

Adjust seasonings to taste.

Lay a sheet of fresh pasta dough on a clean surface.

Cut the pasta sheet into appropriately sized rectangles (for manicotti).

Place a generous amount of butternut squash filling along one edge of each pasta rectangle.

Gently roll the pasta around the filling to form a tube.

Place each manicotti seam-side down in a baking dish.

Pour the Gorgonzola Cream Sauce over the manicotti.

Bake in the preheated oven for 45 minutes, or until the pasta is cooked and the sauce is bubbly.

Serve hot, topped with extra gorgonzola cream sauce, parsley, and hazelnuts (optional).