Preheat oven to 425°F. Halve the squash lengthwise, scoop out seeds, and peel. Place on a baking sheet, cut side down, and rub with olive oil. Season with salt and pepper.
Return to oven and roast for an additional 40 to 50 minutes, or until the entire squash is to your desired tenderness. Sprinkle with chopped pecans in the last 5 minutes of roasting.