Preheat a cast-iron skillet or griddle over medium-high heat until a few drops of water sizzle.

Lightly brush the outside of each flour tortilla with mayonnaise and set aside.

Shape a quarter of the ground beef into a patty and press it onto one side of each tortilla. Season with salt, pepper, and garlic powder.

Place the tortillas beef-side-down into the skillet and cook for 2 to 3 minutes until crispy.

Flip the quesadillas, sprinkle cheese on the beef side, fold, and cook until the outside is golden and crispy.

Remove from skillet, let rest for 1 to 2 minutes, then slice into triangles.