Preheat the oven to 350°F / 175°C and mix ketchup and brown sugar in a small bowl to make the glaze.
Combine ground beef, crushed crackers, eggs, milk, onion, garlic powder, salt, and black pepper in a large bowl until just mixed.
Shape the mixture into a loaf in a 9x5-inch loaf pan or on a rimmed baking sheet, then brush half the glaze over the top.
Bake for 45 minutes, then brush the remaining glaze over the meatloaf and bake for 15 more minutes until the internal temperature reaches 160°F / 71°C.
Let the meatloaf rest for 5 minutes before slicing to keep the juices inside.