Remove chicken breasts from refrigeration 30-45 minutes before cooking. Preheat oven to 375°F (190°C) with rack positioned in middle.
Place chicken breasts between two sheets of plastic wrap. Using a meat mallet or heavy skillet, gently pound thicker parts to achieve uniform 3/4-inch thickness throughout.
In a small bowl, combine salt, pepper, garlic powder, onion powder, paprika, and cayenne (if using). Pat chicken completely dry with paper towels. Brush chicken with olive oil, then apply dry rub mixture evenly on all surfaces.
Line baking sheet with parchment paper. Place seasoned chicken on sheet with at least 1 inch between pieces. Bake for 15-18 minutes until internal temperature reaches 155°F (68°C) at thickest point.
While chicken is cooking, combine BBQ sauce, honey (if using), and apple cider vinegar in a small bowl.
Remove chicken from oven when it reaches 155°F. Increase oven temperature to 425°F (220°C). Generously brush chicken with BBQ sauce mixture, coating all exposed surfaces.
Return chicken to oven for 5-7 minutes until sauce caramelizes and internal temperature reaches 165°F (74°C).
Remove from oven and let rest for 5 minutes before serving. Apply a final light coating of BBQ sauce before serving for maximum flavor impact.