Makes: 6 servings. Prep: 20 minutes. grill: 6 minutes.
In a medium-size saucepan, combine tomato sauce, vinegar, sugar, Worcestershire sauce, pickle relish, garlic powder and pepper. Heat over medium-high heat until bubbly. Cook 5 minutes. Set aside.
Heat gas grill to medium-high heat or prepare charcoal grill with medium-hot coals.
In a large skillet, cook bacon over medium-high heat until just crisp, about 5 minutes. Cool on a paper towel-lined plate, then crumble. In a large bowl, combine 1/2 cup of the BBQ Sauce, the crumbled bacon, ground beef, garlic powder and pepper. Mix until well combined, then shape into six 4-inch burger patties, each 3/4-inch thick.
Grill burgers 4 minutes. Flip over and grill an additional minute. Top with cheese and continue to grill 1 minute more, or to desired doneness.
Spread a little BBQ Sauce onto rolls. Top each half with a lettuce leaf, tomato and onion slice. Once cooked, top each with a burger patty, then spread with a little BBQ Sauce. Serve with remaining sauce on the side.