Preheat the oven to 400°F (200°C). Toss the cubed sweet potatoes with a tablespoon of olive oil and spread them in a single layer on a baking sheet. Roast until tender and caramelized, about 30-35 minutes, smelling sweet and smoky as they brown.
Meanwhile, heat the remaining olive oil in a large pot over medium heat. Add the minced garlic, cumin, and smoked paprika. Sauté for about 1 minute until the garlic is fragrant and spices bloom, filling the kitchen with a warm aroma.
Pour in the vegetable broth and bring to a gentle simmer, allowing the flavors to meld for about 5 minutes. The mixture will start to smell savory and rich.
Add the roasted sweet potatoes and rinsed black beans to the simmering broth. Use a spoon to gently mash some of the sweet potatoes directly in the pot—this helps develop a creamy texture while still leaving some chunks for contrast.
Using an immersion blender, blend the soup until mostly smooth with some texture remaining, or carefully transfer to a blender and puree until you reach your desired consistency. Be sure to leave some chunks for visual appeal.
Return the soup to the heat and cook for another 5 minutes, stirring occasionally. Season with salt and pepper to taste. The soup should be warm, fragrant, and slightly thickened, with a smoky orange hue.
Spoon the hot, smoky sweet potato and black bean soup into bowls. Garnish with fresh herbs or a drizzle of olive oil if desired. Serve immediately for the best flavor and texture.