1. Preheat oven to 375°F (190°C) and grease a skull-shaped baking mold with cooking spray.

2. In a skillet over medium heat, cook ground beef and onion until beef is browned. Drain fat.

3. Stir in ketchup, mustard, garlic powder, salt, and pepper. Remove from heat and let cool slightly.

4. Mix shredded cheese into the beef mixture.

5. Separate biscuit dough and press each piece into the cavities of the mold, forming a shell.

6. Fill each shell three-quarters full with beef and cheese mixture.

7. Fold excess dough over the filling to seal the skull shape.

8. Bake for 15–18 minutes until dough is golden brown.

9. Allow to cool 5 minutes, then carefully remove skulls from the mold.

10. Serve warm with extra ketchup or dipping sauces.