In a large skillet over medium heat, brown the ground beef, breaking it apart as it cooks. Add the diced onion and cook until softened, about 5 minutes. Drain excess fat, then mix in minced garlic, salt, black pepper, ketchup, and mustard. Stir for 1-2 minutes and remove from heat.

On a floured surface, roll out the refrigerated pizza dough into a large rectangle, about ¼ inch thick. Transfer the dough to a lightly greased baking sheet.

Spread the cooked beef mixture over the pizza dough, leaving a small border for sealing. Sprinkle the shredded cheese on top. Gently roll the dough into a log shape, then slice into 1 to 1½-inch pieces.

Preheat your oven to 375°F (190°C). Place the sliced rollups on a parchment-lined baking sheet. Mix melted butter with garlic powder; brush over the rollups. Bake for 15-18 minutes until golden brown and cheese is bubbling.

Remove from the oven and let cool for a few minutes. Optionally brush with extra garlic butter and sprinkle with dried parsley before serving.