Combine flour, salt, pepper and garlic powder, and sprinkle evenly over meat. Work into meat to distribute evenly. This will help bind the meat together when cooked.
Place meat in a large bowl, and add remaining ingredients except cheese. Using your hands, mix thoroughly. Divide mixture into 3 equal portions. Divide each portion into 4 equal portions to make 12 patties. When forming burger patties, press firmly to help keep burgers intact while cooking.
Place on a medium-hot grill, griddle or skillet and brown on one side. Flip over, cook for a couple of minutes more. Top with cheese, and cook until melted. Place in buns, and serve with condiments, if desired.