Heat oven to 375°F (190°C). In a pan, cook ground beef with garlic, salt, onion flakes, and pepper until browned, about 5–7 minutes.
Lower the heat. Stir in cream cheese until melted, then mix in BBQ sauce and Dijon mustard. Turn off the heat.
Tip: If the mixture looks dry, add a splash of water or extra sauce.
Cut the Hawaiian rolls in half horizontally. Place the bottom halves in a 9x13-inch dish.
Sprinkle 1 cup cheddar over the rolls. Add the beef mixture, then the bacon, and finish with the rest of the cheese. Place the roll tops back on.
Mix melted butter with sesame seeds. Brush it over the tops of the rolls.
Cover the dish with foil and bake for 20 minutes. Remove foil and bake 5–10 more minutes until golden.
Let cool for 5 minutes, then slice and enjoy.