01 - Preheat oven to 400°F. Toss cubed butternut squash with olive oil, spread on a baking sheet, and roast 20 to 25 minutes until tender and caramelized. Let cool slightly.
02 - Puree roasted squash until smooth in a food processor. Combine with ricotta, Parmesan, salt, pepper, and nutmeg; mix evenly and set aside.
03 - On a clean surface, mound flour and create a well in the center. Add eggs and salt, gradually incorporate flour with a fork, then knead dough until smooth, about 10 minutes. Wrap in plastic and rest for 30 minutes.
04 - Divide dough in half and roll each portion into a thin sheet about 1/16 inch thick, dusting with flour to prevent sticking.
05 - Place teaspoon-sized mounds of filling 2 inches apart on one dough sheet. Brush water around each mound, cover with second sheet, press to seal without air pockets, and cut into squares.
06 - Bring a large pot of salted water to a gentle boil. Cook ravioli in batches for 3 to 4 minutes until they float. Remove with a slotted spoon.
07 - Melt butter in a skillet over medium heat. Add sage leaves and cook 2 to 3 minutes until butter is golden and fragrant.
08 - Drizzle sage butter over ravioli and garnish with extra grated Parmesan. Serve immediately.