Heat olive oil in a skillet over medium heat. Add sweet potatoes and cook until tender, about 10 minutes.
Add black beans, cumin, chili powder, salt, and pepper to the skillet. Cook for another 5 minutes.
Heat another skillet over medium heat. Place a tortilla in the skillet, sprinkle with cheese, and add the sweet potato and black bean mixture. Top with more cheese and another tortilla.
Cook until the bottom tortilla is golden brown, then flip and cook the other side until golden brown and the cheese is melted. Repeat with remaining tortillas.