Preheat the oven to 350 degrees Fahrenheit.
Add the ground beef, milk, breadcrumbs, onions, eggs, salt, and black pepper into a large bowl. Mix all the ingredients together. This will keep the meatloaf moist and flavorful.
In a small bowl, whisk together the garlic powder, brown sugar, and ketchup for your sauce.
Either place the meat mixture into a loaf pan or shape the meat into a loaf yourself and place it on a sheet pan lined with a baking sheet. Place it in the oven for a total cooking time of about 1 hour. (Use a meat thermometer to discern when the meatloaf’s internal temperature has reached 160 degrees Fahrenheit before removing it from the oven.)
Remove the meatloaf from the oven and douse it with your sauce. Let it cool for a few minutes and then slice it.
Serve the meatloaf. Store the leftovers in aluminum foil or plastic wrap in your refrigerator.