Heat a large skillet over medium-high heat and add the ground beef.
Cook the ground beef, breaking it apart with a spatula, until it begins to brown, about 4-5 minutes.
Add the chopped onion and minced garlic to the skillet with the beef and cook for another 3-4 minutes until the onion is softened.
Stir in chili powder, ground cumin, smoked paprika, salt, and black pepper. Cook for 1-2 minutes until the spices are fragrant and the beef is fully cooked. Remove from heat.
Wipe out the skillet and spray lightly with cooking spray. Place one tortilla in the skillet over medium heat.
Sprinkle 1/2 cup shredded cheddar cheese evenly over the tortilla.
Spread about 1/4 of the cooked ground beef mixture evenly over the cheese.
Sprinkle 1 tablespoon of chopped cilantro over the beef.
Top with another 1/2 cup shredded cheddar cheese.
Place a second tortilla on top and press down gently.
Cook for 3-4 minutes until the bottom tortilla is golden brown and the cheese begins to melt.
Carefully flip the quesadilla using a large spatula and cook the other side for another 3-4 minutes until golden brown and cheese is fully melted.
Remove from skillet and let rest for 1-2 minutes before cutting into 4 wedges.
Repeat the process with the remaining tortillas and filling to make 4 quesadillas total.