Tear one hamburger bun into pieces. Place in food processor or blender container. Cover; pulse on and off, to form fine crumbs.
Combine bread crumbs, beef, garlic and chili powder in medium bowl, mixing lightly but thoroughly. Lightly shape into eight 1/2-inch thick mini patties.
Place patties on grill over medium, ash-covered coals. Grill, covered, 8 to 9 minutes (over medium heat on preheated gas grill, 9 to 10 minutes) until instant-read thermometer inserted horizontally into center registers 160°F, turning occasionally. Evenly top with cheese during last minute of grilling.
Place burgers on bottoms of remaining eight buns. Top with desired Toppings. Close sandwiches.
Nutrition information per serving: 201 Calories; 54 kcal Calories from fat; 6 g Total Fat; 3 g Saturated Fat; 0 g Monounsaturated Fat; 40 mg Cholesterol; 266 mg Sodium; 21 g Total Carbohydrate; 3.1 g Dietary Fiber; 16 g Protein; 2.3 mg Iron; 4.1 mg Niacin; 0.2 mg Vitamin B6; 1.1 mcg Vitamin B12; 3.4 mg Zinc; 28.8 mcg Selenium; 50.8 mg Choline;