Preheat oven to 425F. Mix together the beef, onion, bread crumbs, eggs, garlic and onion powder. Flatten out on a 10x15" pan (foil lined if you like), to fit the amount of buns you have. Making it larger than the buns to allow for shrinkage. If you use a fattier meat the more shrinkage there will be.
Bake until browned and no longer pink inside about 8-10 min. Pat off excess fat with a paper towel.
Sprinkle with cheese and bacon and then run under a broiler until cheese is melted. Using a pizza cutter slice into desired sizes. Serve on the slider buns with toppings of your choice.
Nutrition calculation is an estimation only. If you need nutritional calculations for medical reasons, please use a source that you trust.