Preheat your oven to 350°F (175°C).
In a large bowl, combine the ground beef, breadcrumbs, and chopped onion.
Add the milk, egg, salt, pepper, and garlic powder to the mixture.
Mix the ingredients until well combined, but do not overmix.
Shape the mixture into a loaf and place it in a baking dish.
In a separate bowl, combine brown sugar and ketchup for the glaze.
Spread half of the glaze over the meatloaf.
Bake in the preheated oven for 45 minutes.
After 45 minutes, remove from the oven and spread the remaining glaze.
Return to the oven and bake for an additional 15 minutes.