Heat the olive oil in a large pot over medium heat. Add the onion, garlic, and red bell pepper. Cook for 5 minutes until the vegetables soften.
Stir in the cumin, chili powder, smoked paprika, salt, and black pepper. Cook for 1 minute until the spices become fragrant.
Add the black beans, corn, diced tomatoes, and vegetable broth. Stir to combine.
Bring the soup to a simmer and cook for 15 minutes, stirring occasionally.
Remove the pot from the heat. Stir in the lime juice.
Ladle the soup into bowls and top with chopped cilantro and avocado slices.