1. Preheat the oven to 400 degrees F.
2. Cut the squash to divide the neck from the bulbous bit, setting the bulbous bit aside. Using a spiralizer, turn the neck into noodles. If you have a larger squash or a small spiralizer, it may be easier to cut the neck in half lengthwise.
3. Toss the noodles with oil, salt and pepper. Spread on a parchment-lined baking sheet and roast until soft, about 10 minutes.
4. While the noodles are roasting, scoop the seeds and use a spoon to hollow out the bulb a bit. With a pumpkin carving kit or knife, carve a face onto the front of the bulb.
5. When the noodles are cooked, scoop them carefully into the hollow of the bulb, mounding up to form a brain shape above the top of the bulb.