In a large stock pot, heat the olive oil over medium heat.
When warm, add the diced onion. Saute until translucent, approximately 2-3 minutes.
Add the milk to the stock pot. Bring to a boil.
Add the sweet potatoes, cumin, chili powder, coriander, and paprika. Cook the sweet potatoes at a boil for approximately 10-12 minutes until fork tender.
If you want to leave some sweet potato chunks in the soup, remove approximately 1/4 cup and set aside in a small bowl. Using an immersion blender or regular blender, puree the rest of the sweet potato in the milk base until smooth.
Add any reserved sweet potato back into the pot. Mix in the black beans and corn.
Season with salt to taste and additional spices as necessary. Serve immediately with variety of toppings.