Slice kabocha squash in half and scoop out the seeds. Put cut side up on a roasting pan or baking sheet. Drizzle olive oil on top and roast at 450° for 20-30 minutes, or until tender. Let cool and remove skin. Chop into medium chunks.
Heat olive oil in a large soup pot. Add onion and cook until translucent.
Add apple and chipotle in adobo. Cook for a couple of minutes. Add garlic and cook for 30 seconds more.
Add cumin and vegetable broth. Cook until apple is tender. Add kabocha squash and cook a few minutes more. Set aside to cool.
Blend in a food processor or blender until smooth. If you don't want chipotle seeds, strain soup. Reheat on stove top. Add salt and pepper, to taste.
Serve with cilantro garnish and vegan sour cream, if desired.