Heat a large skillet over medium-high heat and add the ground beef.
Cook the ground beef, breaking it apart with a spatula, until browned and cooked through, about 5-7 minutes.
Add the diced onion and minced garlic to the skillet with the beef and cook for 2-3 minutes until the onion is softened.
Stir in ground cumin, chili powder, smoked paprika, salt, and black pepper. Cook for an additional 1 minute to toast the spices.
Remove the skillet from heat and stir in the black beans and chopped cilantro. Set aside.
Heat a clean large skillet or griddle over medium heat and brush lightly with olive oil.
Place one tortilla on the skillet and evenly sprinkle 1/2 cup shredded cheddar cheese over half of the tortilla.
Spread 1/4 of the beef and bean mixture over the cheese, then sprinkle another 1/4 cup shredded cheddar cheese on top of the beef mixture.
Fold the tortilla over to cover the filling and press gently with a spatula.
Cook for 3-4 minutes until the bottom is golden brown and the cheese begins to melt, then carefully flip and cook the other side for another 3-4 minutes until golden and cheese is fully melted.
Remove the quesadilla from the skillet and let it rest for 1 minute before cutting into wedges.
Repeat the process with the remaining tortillas and filling.
Serve the quesadillas warm with salsa and plain Greek yogurt on the side.