Split pumpkin top to bottom; remove seeds. Rub lightly with oil all over and place on parchment-lined sheet pan. Roast in 350° oven until soft throughout (a wooden pick will pierce easily). Cool to handle and remove skin. Set aside. Sauté onions and shallots in butter over medium heat until very soft, approx. 6 min. Add apples and cook until soft, approx. 2 min. Add pumpkin, stock, vinegar, spices and fresh thyme. Bring to a simmer and cook 10 min. Puree with a stick blender or (carefully) do so in counter-top blender. Pass soup through a sieve back into pot, discarding any solids. Finish with apple juice. Serve hot and garnish with toasted croutons, blue cheese crumbles and/or bacon, as desired.