Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.
Place one tortilla on the prepared baking sheet. Sprinkle half of the shredded mozzarella cheese evenly over the tortilla.
In a medium-sized bowl, combine the cooked shredded chicken, diced tomatoes, diced red onions, sliced black olives, chopped fresh cilantro, chili powder, cumin, garlic powder, salt, and pepper. Mix well until all the ingredients are evenly distributed.
Spread half of the chicken mixture over the cheese on the tortilla. Make sure to spread it out evenly, covering the entire surface.
Place the second tortilla on top of the chicken mixture, pressing down gently to ensure it sticks together. At this point, you can also add any optional toppings you desire, such as a dollop of sour cream, a spoonful of guacamole, or a drizzle of salsa. These toppings will add even more flavor to the quesadillas.
Once all the ingredients are assembled, place the baking sheet in the preheated oven and bake for about 10-12 minutes, or until the cheese is melted and bubbly, and the tortillas are golden brown and crispy.Remove the quesadillas from the oven and let them cool for a few minutes before slicing them into wedges. This will allow the cheese to set slightly, making it easier to cut without the fillings spilling out.