Method:
Preheat the oven to 400° F. Season hens with salt and pepper and rub with butter, sugar, lemon and orange zest. Halve orange. Juice one half and slice other. Stuff each bird with orange juice and orange slices, shallots and rosemary.
Heat a large pan over medium heat. Brown hens on all sides, 6 to 10 minutes.
Meanwhile, prepare acorn squashes by quartering and removing seeds. Place them in a roasting pan and dot with butter, drizzle with syrup and sprinkle with allspice. Place hens breast side up in the same roasting pan and roast until browned and cooked through, about an hour.
Remove hens and let rest for juices to redistribute. Continue cooking acorn squash 10 to 15 minutes longer, until tender. Garnish with green onions and serve immediately.