Preheat oven to 375°F and grease a 12-cup muffin tin.

Mix breadcrumbs and milk, let sit 2 minutes.

Add beef, egg, carrot, onion, ketchup, Worcestershire, salt, and pepper.

Mix with your hands until just combined. Don't overmix.

Divide into the muffin cups and press down gently.

Spoon a little ketchup on each one.

Bake 18–22 minutes until cooked through.

Let rest 5 minutes before removing.