In a medium pot, bring salted water to a boil. Add the diced sweet potatoes and cook until tender, about 10-12 minutes. Drain and return to the pot.
Add olive oil, smoked paprika, cumin, salt, and pepper to the cooked sweet potatoes. Mash them lightly with a fork, leaving some chunks for texture.
Heat a large skillet over medium heat. Place one tortilla in the skillet. Spread a portion of the sweet potato mixture over half of the tortilla, then sprinkle with a quarter of the cheese, and top with some black beans and cilantro.
Fold the tortilla in half, pressing it down gently. Cook for about 3-4 minutes on one side, until golden and crispy. Carefully flip it and cook for another 3-4 minutes on the other side, until the cheese melts.
Repeat the assembly and cooking process with the remaining tortillas and filling ingredients.
Once cooked, remove the quesadillas from the skillet and cut them into wedges. Serve warm with avocado slices and lime wedges on the side.
Notes
Optional to add cilantro and serve with avocado and lime.