Preheat the oven to 400ºF. On a large rimmed baking sheet, toss butternut squash with a drizzle of olive oil and sprinkle with salt and pepper. Roast in the oven until lightly brown and beginning to caramelize, stirring every 10 minutes or so, about 60 minutes.
Place roasted squash, 2 tablespoons olive oil, sage, parsley, Parmesan, and pine nuts In the bowl of a food processor and pulse a few times. Scrape down the sides if necessary, and continue to pulse or process until a smooth pesto forms. If you’d like a thinner pesto, stream in olive oil while the motor is running until you’ve reached the desired consistency.