Preheat oven to 400 degrees.
Place chicken breasts on a pan and sprinkle with approximately 1 Tbsp of Cajun Seasoning. Place in oven and bake until 165 degrees Fahrenheit.
While chicken is cooking slice mangos and wash spinach leaves. Set aside.
Slice caramelized onion cheese. Set aside.
Slice loaf of bread into 12 slices.
Place avocado mayo, 1 Tbsp cajun seasoning, onion salt and garlic powder in a bowl. Mix thoroughly. Set aside.
Place bread slices on a cookie sheet, brush with olive oil and sprinkle with garlic powder and onion salt. Set aside.
Once chicken is done turn the oven on a medium to high broil. Place cookie sheet of bread slices under broiler until browned to desire. Remove from oven.
Slice chicken breasts and set aside.
Spread cajun mayo on all 12 slices of bread. Place chicken slices on top of 6 pieces of bread.
Top chicken with caramelized onion cheese, spinach and mango.
Sprinkle sandwich with smoked paprika and enjoy!