Mix together the ranch dressing and BBQ sauce in a bowl. Set aside.
Season both sides of the chicken breasts with salt, pepper and garlic powder and place in a ziploc bag.
Into the bag, pour half the prepared dressing over chicken breasts. Squish it around to evenly coat. Refrigerate 30 minutes to marinate.
When ready, preheat oven to 400ºF. Spray an 11 x 7 (or 9x13) baking dish with nonstick cooking spray.
Cook bacon in large skillet on medium heat until bacon is almost fully cooked (not crisp.) Remove bacon from skillet, reserving 1 Tablespoon of drippings in skillet. Set aside bacon on paper towels.
Add potatoes to reserved drippings; season with salt, pepper and garlic powder. Cook about 5 minutes, stirring occasionally. Remove from heat.
Cut up bacon. Add to potato mixture; mix lightly. Spoon potatoes and bacon into a 13x9-inch baking dish. Pour remaining prepared dressing over potatoes and stir to coat.
Remove chicken from marinade; discard marinade. Place chicken evenly over potato mixture in baking dish.
Cover with aluminum foil. Bake 45 minutes.
Remove foil and top with shredded cheese.
Cover again and place back into oven for an additional 8-10 minutes until cheese is melted and chicken is thoroughly cooked (165f degrees) and potatoes are fork tender.