Prepare the coals in your BBQ or preheat the grill to MEDIUM-HIGH heat if using a gas BBQ.
In a large bowl, mash the bread and milk together with a fork until it forms a chunky paste. Add the salt, pepper, garlic, BBQ sauce, and Worcestershire sauce and mix well.
Add the ground beef. breaking the meat up with your hands as you add it. Mix everything together until just combined. Divide the mixture into 6 equal portions and form balls. Flatten the balls into ¾-inch patties. Use your fingers to form a slight depression in the center of each patty.
Coat both sides of the patties with nonstick cooking spray (I used avocado oil spray) or alternately, oil the grates on your grill.
Grill the burgers, covered, until nicely browned on the first side, 2 to 4 minutes. Flip burgers and continue cooking for a few minutes more until the internal temperature reads at least 160 degrees F. Brush with additional BBQ sauce towards the end of the grilling time, if desired, and top with cheese. Cover and continue to cook until the cheese melts.
Before serving, toast the buns on the cooler side of the grill or under your oven’s broiler, if desired.
Serve on the burgers on buns with desired toppings.