Directions:

Place chicken breasts in a large ziploc bag and pour in barbecue sauce (enough to coat well plus a little extra). Shake around to make sure all of chicken is covered; let sit in refrigerator for at least an hour (I usually do it the night before so flavor really soaks in).
Place chicken breasts in non-greased 9x13-inch glass dish, and pour left-over sauce over breasts. Cover chicken breasts with shredded ham (nice to have extra to scoop over chicken on plate after baking). Sprinkle with 1/2 cup of cheese. Place pineapple rings over top of ham-covered breasts. Spoon a little bit of pineapple juice over the top.
Cover with foil. Bake in oven at 375° F for 30 minutes. Remove foil and bake another 20-30 minutes at 400 degrees. Wait for shredded ham to get a little browned and crispy on top. Then spread remaining cup of shredded cheese over top and return to oven for 5 more minutes until cheese is melted. Remove from oven and let sit 10-15 minutes before serving. Place breasts with toppings on plate; drizzle remaining juice from glass dish over top of chicken on plate.