Season the chicken breast evenly on both sides with garlic powder, smoked paprika, salt, and black pepper.
Preheat a non-stick skillet or grill pan over medium-high heat with a light coating of cooking spray.
Cook the chicken for 6 to 7 minutes per side, or until the internal temperature reaches 165°F (74°C).
Remove chicken from heat and let it rest for 5 minutes before slicing into 1/2-inch strips.
In a large serving bowl, create a base with the chopped romaine lettuce and cooked brown rice.
Arrange the black beans, sweet corn, and cherry tomatoes in sections over the base.
Place the sliced chicken on top of the vegetables.
Drizzle the sugar-free BBQ sauce and Greek yogurt ranch dressing over the entire bowl before serving.