Wash outside of squash. Remove, with a butcher knife, butternut squash stems (at both ends) and cut squash in half lengthwise. You may want to cut it in 4 pieces to make it roast faster. Remove and discard seeds and mushy stringy part.
Put squash in a baking pan and drizzle with olive oil, fresh rosemary and 1/4 tsp garlic powder, ginger, salt and pepper to taste on each half of the squash.
Roast butternut squash in oven for 1 hr and 10 minutes or until a fork pierces the squash easily.
Put squash into a stand up blender and mix for 2-3 min (if you left skin on, less if not) and then transfer to sauce pan –Or- put squash directly into a 4 qt. sauce pan if you have an immersion blender and mix for 2 min or until smooth.
Add vegetable broth and stir together. Cook soup on low covered until soup is heated through.
Storage:Store leftover soup in the refrigerator for up to 5 days or freeze up to 6 months.