Preheat oven to 450 degrees F.
Place squash on a baking sheet and roast until soft 30 to 40 minutes. Scoop out flesh and run though a food mill. Place the puree into a medium saucepan and cook over low heat until almost dry. Add the remaining ingredients and season with salt and pepper to taste. Lay a sheet of pasta dough on a lightly floured work surface and distribute a heaping teaspoon-sized portion of the filling at least 2 inches apart. Use your fingertip or a brush to moisten the edges of the pasta sheet with the egg wash. Carefully place a second sheet of the pasta dough on top of the first and press with your fingertips to separate the rows of filling. Repeat with the remaining dough. With a ravioli cutter or pastry wheel, cut along straight lines on the vertical and horizontal to form each ravioli square. Press the edges closed with your fingertips to seal well. Bring a large pot of salted water to a boil. Carefully drop in the ravioli and cook for about 5 minutes. Drain, plate and spoon butter sauce over and garnish with finely chopped chives.
Melt butter in a medium saute pan over medium heat and cook until the foam subsides and the butter begins to brown, 3 to 4 minutes. Remove from the heat, stir in the hazelnuts and sage and season with salt and pepper to taste.
This recipe has been updated and may differ from what was originally published or broadcast.