Preheat the grill to medium-high; lightly coat the grate with cooking oil. Grill the chicken, turning as needed, for 15 minutes or until cooked through and well-marked. Transfer to a plate. Reduce the grill to medium-low. Spread the mayonnaise just below the center of the tortillas, leaving space on the sides. Top with spinach, tomato, bacon, a cooked chicken breast, Cheddar and avocado.
Firmly fold the bottom half of the wrap over the filling, fold in the sides and roll up to completely enclose filling. Lightly coat the outside with cooking spray. Place the wraps on the grill. Toast for 3 minutes per side or until golden.
Cut each wrap in half on an angle. Serve immediately.
