The key to a crispy quesadilla is not overfilling your tortilla, and using less fat in the pan! I like using an olive oil cooking spray to get my grill pan completely coated but not too greasy. Also make sure to cook the quesadilla low and slow - don't turn the heat up too fast and allow the cheese to melt and the tortilla to cook slowly. This way, you'll end up with a crispy, not soggy, quesadilla every time!