Cut an “X” in the core of each brussels sprout. Place in a large saucepan; add 1 inch of water. Bring to a boil. Reduce heat; cover and simmer for 8-10 minutes or until crisp-tender. Meanwhile, in a large ovenproof skillet, cook bacon over medium heat until crisp. Using a slotted spoon, remove to paper towels; drain, reserving 2 tablespoons drippings. Sauté onion in drippings until tender. Stir in the vinegar, mustard, garlic powder, salt, brussels sprouts and bacon; cook 2-3 minutes longer. Sprinkle with bread crumbs; broil 4-6 inches from the heat for 2-3 minutes or until golden brown.