Preheat oven to 190 C. Coat 9x9 baking dish with lightly with butter. In a large bowl, combine beef, onion, breadcrumbs, BBQ sauce, egg, chili powder, and salt until well mixed. Gently press into bottom of baking dish.
Bake uncovered for 20 to 25 minutes, or until cooked through. Remove from oven and carefully pour off any excess fat if needed.
Adjust oven temperature to broil and place oven rack 6 to 8 inches from heat source. If using a counter top oven like me, switch to the top coil only and leave the rack in the center.
While the beef is cooking, boil the potatoes until tender, skin on or off is up to you. Once the potatoes are done, remove from heat, same pot, add the milk, butter, parsley, and garlic powder, mash with a potato masher until smooth. Stir in bacon. Spread evenly on top of beef mixture and sprinkle with cheese.
Broil for 3-5 minutes or until the cheese is lightly browned. Serve with a vegetable on the side for a nice meal.