In a large skillet over medium heat, brown the ground beef, breaking it apart as it cooks. If using onion, add it when the beef is halfway done and sauté until it softens, about 3-4 minutes. Once cooked through, drain excess grease, then stir in minced garlic, salt, pepper, ketchup, and mustard. Cook for 1-2 minutes until well combined, then remove from heat and set aside.

Preheat your oven to 375°F (190°C). On a floured surface, roll out the crescent roll dough into a large rectangle, pressing the seams together. Aim for a uniform thickness.

Spread the cooked beef mixture evenly over the prepared dough, leaving a small border. Sprinkle shredded cheddar cheese across the beef mixture, then roll the dough up tightly from one end to the other. Slice the roll into 1–1.5 inch pieces.

Place the sliced rollups onto a lined baking sheet, ensuring space between them. Melt some butter and mix in garlic powder. Brush this mixture over the tops of each rollup. Bake in the preheated oven for 12-18 minutes, or until bubbly and golden brown.

Let the Garlic Butter Cheeseburger Rollups cool slightly before serving. Optionally, brush with additional garlic butter and garnish with fresh parsley. Serve warm with dipping sauces like ketchup or ranch.