Preheat your oven to 350°F (175°C) and grease the muffin tin.

In a large mixing bowl, combine ground beef, breadcrumbs, eggs, chopped onion, ketchup, and seasonings. Mix until combined.

Spoon the meat mixture into the prepared muffin cups, filling each about two-thirds full.

Bake in the oven for 25-30 minutes until firm and golden brown.

Let cool for 5 minutes before removing from the tin and serving.