Preheat the oven to 350°F.
Season the ground beef with salt, pepper, garlic powder, and onion powder.
Cook the beef over medium heat, breaking it apart as it cooks, until browned.
Spread mayonnaise on the bottom halves of the slider buns.
Layer the cooked beef evenly over the buns.
Place cheese slices on top of the beef.
Cover with the top halves of the slider buns.
Mix melted butter with mustard and brush it over the tops of the sliders.
Sprinkle sesame seeds over the top.
Bake for 15 minutes until the cheese is melted and the tops are golden brown.
Remove from the oven, add diced onions and pickles, and serve warm.