Heat the oven to 400°F. Lightly grease a standard 12-cup muffin pan, then place it on a rimmed baking sheet to make it easier to handle and to catch any overflow.

In a large bowl, combine the ground beef, breadcrumbs or oats, onion, egg, Worcestershire sauce, salt, black pepper, 1/4 cup barbecue sauce, and about 1/2 cup shredded cheddar cheese.

Mix with clean hands or a large fork just until the ingredients are combined. Avoid kneading or compressing the mixture heavily because overmixing can make the meatloaf dense.

Divide the mixture evenly among the muffin cups, filling each about three-quarters full. Gently shape the portions without packing them tightly.

Bake for 15 minutes. Carefully remove the pan from the oven so you can add the finishing barbecue sauce and cheese.

Spread the remaining 1/4 cup barbecue sauce over the tops and sprinkle with the remaining 1/2 cup shredded cheddar. Return the pan to the oven and bake for another 5 to 10 minutes.

Check the center of a muffin with an instant-read thermometer; the meatloaf should reach 160°F. Let the muffins rest for 5 minutes before removing them from the pan, and drain excess fat if needed.