Preheat the oven to 400 degrees.
Prep the butternut squash: On a cutting board, slice ¼-inch off the stem and bottom with a sharp knife. Cut the squash at the point where the straight part of the neck meets the rounded bulb end. Slice both sections in half. Peel off the skin with a swivel peeler and scoop out the seeds with a spoon. Cut into 1-1/2-inch cubes.
Toss the squash on a large rimmed baking sheet with 2 tablespoons of the olive oil, ½ teaspoon salt and pepper. Spread in an even layer.
Roast 20-25 minutes, until the squash cubes are tender and lightly browned. Let cool for 5 minutes.
Transfer the squash to a food processor. Add the milk, vegan butter, nutmeg, chili flakes and remaining ½ teaspoon salt. Pulse a few times until the squash is the texture you prefer — we like it slightly chunky.
To serve, put the squash in a serving bowl. Drizzle with additional olive oil and garnish with parsley, additional nutmeg and/or chili flakes, if desired.