1. Preheat your oven to 350°F (175°C). Line a rimmed baking sheet with foil and lightly coat it with cooking spray, or grease a loaf pan if you prefer taller slices.

2. Tear the soft white bread into small pieces and place them in a large mixing bowl. Pour the milk over the bread and let it soak for 3 to 5 minutes, then mash with a fork until the mixture forms a thick paste.

3. Add the grated onion, minced garlic, grated Parmesan, Worcestershire sauce, seasoned salt, kosher salt, black pepper, and chopped parsley to the bread-and-milk mixture. Stir until everything is evenly combined.

4. Add the ground beef and eggs to the bowl. Using clean hands, gently mix just until the ingredients are incorporated, being careful not to overwork the meat so the loaf stays tender.

5. Transfer the meat mixture to the prepared baking sheet or loaf pan. Shape it into a loaf about 2 to 3 inches thick, smoothing the top and sides so the glaze can coat the surface evenly.

6. In a separate small bowl, whisk together the ketchup, brown sugar, yellow mustard, and hot sauce if using. Taste and adjust for sweetness or tang to your liking.

7. Spoon about half of the glaze over the top and sides of the meatloaf, spreading it into an even layer. Reserve the remaining glaze for later in the bake.

8. Bake the meatloaf for 30 minutes. Carefully pull it from the oven, spread the remaining glaze over the top, and return it to the oven.

9. Continue baking for another 20 to 25 minutes, or until an instant-read thermometer inserted into the center of the loaf registers 160°F (71°C) and the glaze is bubbly and slightly caramelized.

10. Remove the meatloaf from the oven and let it rest for 10 minutes before slicing. Garnish with extra chopped parsley, slice into portions, and serve warm with your favorite sides.