The quesadilla as a dish has changed and evolved over many years as people have experimented with different variations of it.

In the central and southern regions of Mexico, a quesadilla is a flat circle of cooked corn masa, called a tortilla, warmed to soften it enough to be folded in half, and then filled.

[10] Sometimes, cheese and ham are sandwiched between two flour tortillas, then cut into wedges to serve what is commonly known as a sincronizada (Spanish for "synchronized") in Mexico.

[12][13] The quesadilla is a regional favorite in the southwestern U.S., where it is similar to a grilled cheese sandwich, with the inclusion of local ingredients.

Once the cheese melts, other ingredients, such as shredded meat, peppers, onions, or guacamole may be added, and it is then folded and served.

This type is similar to the Mexican sincronizada; but in the United States, they often also have fajita beef or chicken or other ingredients instead of ham.

[17] A variation that combines the ingredients and cooking technique of a quesadilla with pizza toppings has been described as a "pizzadilla".

[18][19] Even dessert quesadillas are made, using ingredients such as chocolate, butterscotch, caramel and different fruits.