12 Hawaiian sweet or small whole wheat dinner rolls, split
1/4 cup barbeque sauce
1/4 cup pineapple preserves
1 tablespoon packed brown sugar
Combine ground beef and Worcestershire sauce in medium bowl, mixing lightly but thoroughly. Lightly shape into twelve 1/2-inch thick mini patties. Set aside.
Combine sauce ingredients in small saucepan; bring to a boil over medium heat, stirring frequently. Remove from heat.
Place patties on grill until instant-read thermometer inserted horizontally into center registers 160°F, turning occasionally.
Charcoal: Grill over medium, ash-covered coals, uncovered, 8 to 10 minutes. Gas: Grill over medium heat on preheated grill, covered, 9 to 11 minutes.
Meanwhile brush pineapple slices with sauce and place on grill around patties. Grill pineapple 4 minutes, turning once and brushing with additional sauce. Remove pineapple, keep warm. Brush burgers with remaining sauce after turning.
Cut each pineapple slice into thirds. Line bottom of each roll with lettuce, top with burger, then with pineapple piece. Close sandwiches.