I find using one larger tortilla is easier because you can fill the tortilla with a layer of cheese and add your other fillings to one half, then fold the tortilla over after the cheese is melted. This allows the cheese to melt evenly and keeps it in a nice, neat package to flip or remove from the pan. You can also use two tortillas to sandwich your fillings but will need to flip the quesadilla to cook the top side, which can be tricky.