Soak the dried black beans in cold water for at least 8 hours or overnight. Drain well.
Set the Instant Pot’s sauté feature to high heat. Add the olive oil, onion, celery, and bell pepper. Sauté for 6-7 minutes or until the onions turn translucent.
Add the garlic cloves, cumin, chili powder, paprika, dried oregano, and cayenne pepper (if using) and cook, stirring frequently, for 1 minute or until fragrant.
Stir in the broth, chopped tomatoes, drained black beans, and salt. Stir very well until combined. Turn off the sauté feature.
Lock on the Instant Pot lid and pressure cook on high for 45 minutes.
Quick-release the pressure. Remove the lid and stir in the sour cream until combined.
Using an immersion blender, blend the soup to your desired consistency. Alternatively, carefully pour all or part of the soup into a high-speed blender, vent the lid, drape it with a clean dish towel, and blend. If blending, pour the soup back into the pot.
Season the soup to taste with salt and black pepper. Enjoy hot with a dollop of sour cream and desired additional toppings.