01 - Preheat a grill or skillet over medium-high heat.
02 - In a bowl, gently mix ground beef with salt, pepper, garlic powder, and onion powder. Divide into 8 equal portions and shape into small patties slightly larger than the buns.
03 - Brush the cut sides of the slider buns lightly with melted butter. Toast the buns, cut side down, on the grill or skillet until golden. Set aside.
04 - Cook the beef patties for 2-3 minutes per side, until browned and cooked through. In the last minute of cooking, top each patty with a slice of cheese, cover the pan, and let the cheese melt.
05 - Assemble the sliders: Place a cooked patty on each bun bottom, top with 2 pickle slices, and add onions if using. Drizzle with ketchup and mustard if desired. Cover with the bun tops and serve immediately.