Mix together the ranch dressing and BBQ sauce in a bowl.
Season both sides of the chicken breasts with salt, pepper and garlic powder. In a gallon-size ziploc bag, pour half the prepared dressing over chicken breasts. Refrigerate 30 min. to marinate.
Heat 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 Tbsp. drippings in skillet. Set aside bacon on paper towels.
Add potatoes to reserved drippings; season with salt, pepper and garlic powder. Cook about 5 min., 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 over potato mixture.
Cover with aluminum foil. Bake 45 min. Top with 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.