In a large bowl, combine the ground beef, crumbs, egg, milk, ½ cup BBQ, onion, salt, pepper and garlic powder. Mixed together with your hands.
Cut top and bottom off onion, cut in a slit deep enough to cut through all the layers, and peel off skin. Be sure to not cut in half. Then separate the onion into "layers". Use the larger outside layers.
Wrap each "bomb" with 3 slices bacon and secure with toothpicks.
Bake in a dish with sides (to catch grease) at 425 for approx 40 minutes or until internal temp 165.