1. Preheat oven to 400°. Gently toss first 3 ingredients with oil; season with sea salt and pepper, and place in a jelly-roll pan. Bake 35 minutes or until tender and browned. Add garlic, ginger, and garam masala, if desired, and toss well; bake 5 more minutes.
2. Pour wine over squash mixture, stirring to deglaze pan. Let stand 10 minutes. Transfer to a blender; add broth (in batches, if necessary), and puree until smooth. (For smoothest texture, press squash puree through a wire-mesh strainer, discarding solids.)
3. Transfer puree to a large saucepan, and stir in cream. Cook over medium heat 3 to 5 minutes or until heated through. Season with salt and pepper to taste. Ladle into cordial glasses, and garnish with pumpkin seeds, if desired.