Heat oven to 425°. Trim tops and bottoms from squash. Halve squash and scoop out seeds and pulp. Slice into 1-inch-thick wedges.Advertisement
In a large bowl, whisk sugar, oil, fish sauce, vinegar and 1 tbsp lime juice. Toss squash in bowl to coat. Place on 2 foil-lined rimmed baking sheets and roast 20 minutes. Flip, drizzle with marinade, and roast 10 minutes, until squash is tender and browned.
Season squash with salt and 1 tbsp lime juice. Transfer to a platter and scatter mint and scallions on top.