Preheat your oven to 400°F (200°C) and prepare a large baking sheet by lining it with either parchment paper or aluminum foil to simplify cleanup.
In a mixing bowl, combine the ground beef, breadcrumbs, half of the ketchup, the whisked eggs, and the minced onion. Blend the mixture gently by hand or with a sturdy spoon until it just comes together; avoid excessive mixing to keep the texture tender.
Place the meat mixture onto the lined sheet pan and shape it into a firm loaf, roughly measuring 8 by 4 inches.
Brush the surface of the formed meatloaf with the remaining ketchup, spreading it evenly to create a glossy glaze.
Bake the loaf for 35 to 40 minutes, or until the internal temperature reaches 160°F (71°C) when checked with a meat thermometer.
Remove the meatloaf from the oven and let it rest for 5 to 10 minutes before slicing. This allows the juices to redistribute, ensuring moist and flavorful servings.