Add the diced butternut squash, chopped onion & garlic, olive oil, salt, and pepper to a baking sheet
Bake until squash is softened, ~25 mins
While the squash is in the oven, make the dough. Combine squash mixture with sugar & Parmesan or nutritional yeast.
Food processor the flour, eggs, and olive oil, and pulse until the dough comes together into a large ball. Wrap and chill the dough for 30 mins.
Remove the dough, wrap in plastic wrap, and rest it the refrigerator for 30 minutes. Divide dough in four and roll out into large, wide, thin sheets of pasta.
Fill each 2” squared area with a tablespoon of the butternut squash filling. Place a second sheet on top, lightly wetting the edges between each sheet of dough to seal the raviolis. Press down on all the sides of the raviolis. Separate each ravioli with a knife or cutting tool.
Gently place a few raviolis into boiling salted water and cook until the raviolis float and firm up slightly, 2-3 minutes.
Scoop out the ravioli and set aside. In a pan, add 3 tablespoons of the butter, sage leaves, and hazelnuts
Cook until the butter browns deeply, the nuts are heated through, and the sage is fried and crispy. Turn off the heat and add the lemon juice and season to taste.
Swirl in 2 more tablespoons more of chilled butter, to thicken the sauce. Add the cooked raviolis back into the on and serve.
