01 - Preheat grill or large skillet to medium-high heat.
02 - Combine ground beef, salt, black pepper, garlic powder, and onion powder in a mixing bowl. Mix gently until just incorporated.
03 - Divide beef mixture into 12 equal portions. Shape into small patties slightly larger than the buns to account for shrinkage during cooking.
04 - Grill or cook patties for 2–3 minutes per side until browned and cooked to desired doneness.
05 - During the final minute of cooking, place a cheese slice on each patty. Cover and cook until cheese is melted.
06 - Slice slider buns in half. Brush cut sides with melted butter and toast on grill or skillet until golden brown.
07 - Spread ketchup, mustard, and mayonnaise on bottom buns. Place cheeseburger patties on top, followed by pickles and red onion slices. Add top buns and sprinkle with sesame seeds if desired.
08 - Serve immediately while hot.