Prepare outdoor grill for direct grilling over medium-high heat. Spray cut sides of buns with cooking spray; brush 1 side of burgers with 3 tablespoons sauce. Place burgers, sauce side down, on hot grill rack and brush with remaining 3 tablespoons sauce; cover and cook 8 minutes or until internal temperature reaches 160°, turning once. During last 2 minutes of cooking, top burgers with cheese curds and place buns, cut side down, on hot grill rack; cover and cook 2 minutes or until cheese is melted and buns are toasted.
Spread cut sides of buns with mayo; serve burgers in buns topped with lettuce, pickles, red onion and fried onions. Makes 6 burgers.