Heat a large pan over medium-high heat. Brown ground beef and diced onion in pan until it's no longer pink and onion is tender. Drain off any excess fat from pan and return to stove top.
Add in the garlic, seasoned salt and pepper and cook until fragrant, about 30 seconds. Stir in the cream cheese, chopped jalapenos and 1 cup of the cheddar cheese, until the mixture is creamy and combined.
Meanwhile, use a serrated knife to cut the rolls in half. Place the bottom half of the rolls in a 9x13" baking dish and then top with the ground beef mixture in an even layer. Top with the remaining cheese. Place the tops of the rolls back on the sandwiches.
Combine the melted butter with the garlic powder and brush on top of rolls. Sprinkle the tops of the rolls with the sesame seeds. Loosely cover the dish with foil and bake for 10 minutes. Uncover the dish and continue baking an additional 10 to 12 minutes, until the rolls are browned nicely. Serve hot and enjoy!