Prep the oven and pan: Preheat the oven to 375°F (190°C). Line a sheet pan with parchment paper or foil.
Mix the ingredients: In a large bowl, combine the ground beef, seasoned breadcrumbs, eggs, ½ cup of the ketchup, and the packet of onion soup mix. Mix gently with your hands until just combined. (Do not overmix to avoid a tough meatloaf).
Form the loaf: Shape the meat mixture into a freeform loaf and place it directly in the center of your prepared sheet pan.
Add the glaze: Spread the remaining ¼ cup of ketchup evenly over the top and sides of the meatloaf.
Bake: Bake for 30–35 minutes, or until the meatloaf is cooked through and reaches an internal temperature of 160°F (71°C) on a meat thermometer.
Rest and serve: Remove from the oven and let the meatloaf rest on the pan for 5 minutes before slicing and serving.