Guacamole or diced avocados, sour cream, salsa, and lime wedges to serve, if desired
Preheat the oven to 400°F. Line a baking sheet with parchment paper or aluminum foil, and spray with nonstick spray.
Combine the chicken, olives (if using), chili powder, and cheese in a large bowl. Brush a tortilla with olive oil, place it oil side down on a cutting board. Distribute 1/8 of the chicken/cheese mixture over half of the tortilla. Flip the bare half of the tortilla over the filling, and place it on the prepared baking sheet. Repeat with the rest of the tortillas and the rest of the filling.
Bake the quesadillas for 5 minutes, then carefully flip the tortillas with a large spatula and bake for another 8 to 10 minutes, until the top is browned and crispy. Remove the quesadillas, let them sit on a cutting board for 2 minutes, then cut each half moon quesadilla into three wedges.
Serve hot with guacamole, salsa, sour cream and lime wedges, as desired.