1. Heat butter and oil in a large soup pot over medium heat. Add leeks and garlic and sauté, stirring frequently, for a few minutes.
2. Add squash and parsnips and cook for another few minutes. Add the wine and bring to a boil. Cook until it has all but evaporated, 8-10 minutes.
3. Add the stock and/or water and bring to a boil. Reduce the heat and simmer for 30- 40 minutes or until the vegetables are very soft. Remove from heat.
4. Purée the soup using an immersion blender or, if you do not have an immersion blender, allow soup to cool a bit before transferring it in batches to process in a blender or food processor. Return puréed soup to the pot and add cream or coconut milk and maple syrup. Heat over low heat until warmed through, adding more cream or stock, if necessary, to achieve the desired consistency.
5. Add salt and pepper to taste, and serve hot.