In a small saucepan, combine the balsamic vinegar with the brown sugar. Heat over medium heat and bring the mixture to a simmer, stirring constantly. Reduce by half, about 15 minutes. Set aside and let the mixture cool.
Toss the lettuce, avocado, chicken, tomatoes, and mozzarella pearls with the balsamic vinegar dressing and garnish with a chiffonade of basil (optional).
Serve immediately and enjoy!
Recipe by That Oven Feelin' at http://thatovenfeelin.com/chicken-avocado-caprese-salad/