Finely dice the onions into uniform 1/4-inch pieces and measure out all ingredients. Position your oven rack to the middle position and preheat to 425°F with an empty loaf pan inside. This preheating step is crucial—a hot pan will help develop a nice crust on the bottom and sides of the meatloaf, which adds texture and flavor.

In a large bowl, combine the ground beef, room temperature eggs, 4 tablespoons ketchup, 2 teaspoons Worcestershire sauce, salt, pepper, garlic salt, parsley flakes, and diced onions. Mix gently with your hands until just combined—don't overmix, as this can make the meatloaf dense and tough. The mixture should hold together but still feel light and slightly loose.

Carefully remove the hot loaf pan from the oven and lightly spray it with cooking oil to prevent sticking. Transfer the meat mixture from Step 2 into the hot pan and press it down gently but firmly to create an even surface. The sizzle you hear is the Maillard reaction beginning—this creates a flavorful browned crust. Return the pan to the 425°F oven.

Bake at 425°F for 15 minutes. This high initial temperature continues browning the exterior and starts cooking the interior. After 15 minutes, reduce the oven temperature to 375°F—this lower temperature allows the inside to cook through gently without the outside burning.

While the meatloaf continues cooking at 375°F, make the glaze in a small bowl by whisking together 1/2 cup ketchup, 1 teaspoon Worcestershire sauce, and 1 tablespoon brown sugar until smooth. The brown sugar will add a subtle caramelized sweetness to the glaze. Let this mixture sit while the meatloaf cooks for 30 more minutes at 375°F.

After the 30-minute cook time, spread the glaze mixture from Step 5 evenly over the top of the meatloaf using a spatula or the back of a spoon. Return the pan to the 375°F oven and bake for 45 more minutes. I like to check the glaze at around the 35-minute mark—if it's browning too quickly, you can tent the pan loosely with foil to prevent over-darkening. The total cooking time ensures the interior reaches a safe temperature while the glaze caramelizes beautifully.

Remove the meatloaf from the oven and let it rest in the pan for 10 minutes before slicing. This resting period allows the juices to redistribute throughout the meat, keeping it moist when you cut into it. Slice and serve with your favorite sides—the glaze should have a nice caramelized appearance.