Reserve 1/4 cup barbecue sauce. Shape meat into 4 (1/2-inch-thick) patties.
Broil, 4 to 6 inches from heat, 7 to 9 min. on each side or until done (160°F), brushing occasionally with remaining barbecue sauce for the last few minutes. Top with Singles. Broil 1 min. or until Singles begin to melt.
Fill rolls with lettuce, tomatoes, burgers, reserved sauce and bacon.