Preparation Combine first 4 ingredients in heavy medium saucepan. Boil over medium heat until reduced to 1 1/3 cups, about 30 minutes. Pour into bowl. Mix in ginger. Cool. (Can be made 1 day ahead. Cover and chill.) Preheat oven to 400°F. Place squash on baking sheet. Brush squash on all sides with sesame oil. Turn squash, 1 cut side down, and bake 15 minutes. Turn squash, skin side down. Brush squash with some hoisin mixture. Bake until tender and well glazed, brushing occasionally with some hoisin mixture, about 50 minutes. Preheat broiler. Generously baste squash with hoisin mixture. Sprinkle with salt. Broil until bubbling, about 2 minutes. Baste with any remaining hoisin mixture. Sprinkle with onions and sesame seeds.
Preparation Combine first 4 ingredients in heavy medium saucepan. Boil over medium heat until reduced to 1 1/3 cups, about 30 minutes. Pour into bowl. Mix in ginger. Cool. (Can be made 1 day ahead. Cover and chill.) Preheat oven to 400°F. Place squash on baking sheet. Brush squash on all sides with sesame oil. Turn squash, 1 cut side down, and bake 15 minutes. Turn squash, skin side down. Brush squash with some hoisin mixture. Bake until tender and well glazed, brushing occasionally with some hoisin mixture, about 50 minutes. Preheat broiler. Generously baste squash with hoisin mixture. Sprinkle with salt. Broil until bubbling, about 2 minutes. Baste with any remaining hoisin mixture. Sprinkle with onions and sesame seeds.