Preheat your oven to 350℉. Line a large baking sheet with parchment paper. Slice the Hawaiian rolls in half and place the bottom halves, cut-side up, on the pan.
Heat a large skillet over high heat. Add the beef and onions. Cook for 5-6 minutes until no longer pink. Stir in the salt, black pepper, and garlic powder. Remove from the heat.
Spread desired condiments on the buns. I typically do mustard and ketchup on bottom buns, and mayonnaise on top buns.
Place a pickle slice per bottom bun. Spoon the ground beef all over, layer on the cheese, then place the top buns over top.
Brush the tops with melted butter and sprinkle on sesame seeds.
Bake for 12-13 minutes until the cheese is melted.