Heat the oil in a saucepan over medium heat, add the onion and saute until the onion becomes golden-brown.
Add the ginger and coriander and stir to mix, then add the squash and carrots and cinnamon.
Cook, stirring, about 5-8 minutes until the squash starts to brown.
Add the water or vegetable stock and half the soymilk and bring to a boil. Lower the heat to a simmer, and cover the saucepan.
Cook until the squash is tender, about 30 minutes.
In a blender, or using an immersion blender if you have one, process the soup until it turns smooth and velvety. Be careful while handling the hot ingredients and liquid.
Return the soup to the saucepan and add the rest of the soymilk. Warm until heated through.
Ladle into a bowl, sprinkle some more cinnamon on top.