- Preheat oven to 375°F and grease a 12-cup muffin tin. 
- Cook ground beef in skillet until browned, then add onions and cook 2–3 minutes. Drain grease. 
- Stir in ketchup, mustard, garlic powder, salt, and pepper. Let mixture cool slightly. 
- Flatten biscuit dough pieces into 4-inch circles and press into muffin cups. 
- Spoon 2 tablespoons of beef mixture into each dough cup and top with cheese. 
- Add optional toppings such as bacon or pickles. 
- Bake for 15–18 minutes until golden brown and cheese is melted. 
- Let cool 3–4 minutes before removing from the pan. 
- Serve warm and enjoy your cheeseburger cups!