In a large pot or Dutch oven, heat oil over medium heat. Add onion, garlic, and ginger; cook, stirring occasionally, until softened and fragrant, 5 to 7 minutes.
Add pumpkin, corn, tomatoes and green chiles, and mild green chiles, stirring until well combined. Stir in broth, cream, salt, white pepper, cumin, and chili powder. Bring to a gentle boil. Reduce heat to medium-low and cook, stirring occasionally, 10 to 15 minutes. Garnish with cilantro, crème fraiche, and pumpkin seeds, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/southwest-pumpkin-soup/