1. Preheat the oven to 350°F. Lightly grease a rimmed baking sheet with butter.

2. Heat the olive oil in a large skillet over medium-high heat. Add the diced onion and cook for 2–3 minutes until softened.

3. Add the ground beef to the skillet. Break it apart with a spatula and season with the salt, black pepper, and garlic powder.

4. Cook the beef until fully browned, stirring occasionally and breaking up any large pieces.

5. Remove the skillet from the heat and carefully drain any excess grease. Stir the mayonnaise into the cooked beef mixture until evenly combined.

6. Slice the dinner rolls in half horizontally, keeping the tops and bottoms together as much as possible.

7. Arrange the bottom halves of the rolls on the prepared baking sheet. Layer the sliced cheddar cheese evenly over the bread.

8. Spread the beef mixture evenly over the cheese layer, then sprinkle the shredded cheddar cheese on top.

9. Place the top halves of the rolls over the filling.

10. Brush the tops with the melted butter and sprinkle with sesame seeds.

11. Bake for 12–15 minutes, or until the cheese is melted and the tops are lightly golden.

12. Remove from the oven, let cool for a few minutes, then cut into individual sliders and serve warm.