Preheat your air fryer to 375°F (190°C).
Peel and cube the sweet potatoes, then place them in a pot of boiling water. Cook until tender, about 10 minutes. Drain and let cool slightly.
In a mixing bowl, mash the cooked sweet potatoes with a fork. Add the black beans, cumin, chili powder, garlic powder, onion powder, and salt. Mix until well combined.
Warm the corn tortillas slightly in the microwave for about 30 seconds to make them pliable.
Spoon about 2-3 tablespoons of the sweet potato and black bean mixture onto the center of each tortilla.
Roll the tortilla tightly around the filling and place seam-side down in the air fryer basket. Repeat with the remaining tortillas.
Lightly spray or brush the taquitos with cooking spray or olive oil for a crispy texture.
Air fry the taquitos at 375°F (190°C) for 10-12 minutes, or until golden brown and crisp, flipping them halfway through the cooking time.
Serve warm with your favorite salsa or guacamole.