Arrange the chicken breasts in a baking dish and top with 1/3 of the barbecue sauce; rub in the barbecue sauce, then top with pineapple chunks.
Add remaining barbecue sauce on top and cover with plastic wrap; place in the fridge for 30 minutes and up to 2 hours.
When ready to bake, preheat the oven to 400˚F. Remove plastic wrap. Drizzle olive oil over the chicken.
Bake uncovered for 32 to 35 minutes or until the chicken's internal temperature reads 165˚F. Use an Instant Read Meat Thermometer to check for doneness. Cooking time will depend on the size and thickness of the chicken breasts.
Remove from oven; let stand 5 minutes before serving.