In a large soup pot or dutch oven over medium heat, add the olive oil and onions and cook until the onions are translucent, about 5 minutes. Add the garlic and cook until fragrant, about 1 minute. Add the sweet potatoes and vegetable broth. Bring to a boil and then reduce heat to a simmer. Cover and simmer until the potatoes have softened, about 20 to 30 minutes.

Using a blender, food processor, or immersion blender, puree the cooked ingredients. Return the puree to the pot and add the jalapeno pieces, corn, salt, cayenne, cumin, black pepper, cinnamon, nutmeg, and Tabasco. Stir to combine. Bring to a simmer and cook, covered, for 20 to 30 minutes. Stir occasionally. Add additional vegetable broth to desired consistency. It is a thick soup. Serve hot. Garnish with thin slices of jalapenos or green onions if desired.