Prepare the Meat Loaf:
Preheat your oven to 350°F (175°C).
Line a baking sheet with parchment paper or lightly coat with non-stick cooking spray. Alternatively, you can use a loaf pan.
In a large mixing bowl, combine the ground beef, breadcrumbs, grated Parmesan cheese, beaten egg, finely chopped onion, minced garlic, milk, ketchup, Worcestershire sauce, dried thyme, dried oregano, salt, and black pepper. Mix until well combined, but do not overmix to avoid a tough meat loaf.
Transfer the meat mixture to the prepared baking sheet or loaf pan. Shape it into a loaf form, ensuring it's even and compact.
Prepare the Glaze:
In a small mixing bowl, combine the ketchup, brown sugar, Dijon mustard, and apple cider vinegar. Mix until smooth and well combined.
Spread half of the glaze over the top of the meat loaf, reserving the rest for later.
Bake the Meat Loaf:
Place the meat loaf in the preheated oven and bake for 45 minutes.
After 45 minutes, remove the meat loaf from the oven and spread the remaining glaze over the top.
Return the meat loaf to the oven and continue baking for an additional 15-20 minutes, or until the internal temperature reaches 160°F (71°C) and the glaze is caramelized.
Rest and Serve:
Once the meat loaf is fully cooked, remove it from the oven and let it rest for 10 minutes before slicing. This allows the juices to redistribute, ensuring a moist and tender meat loaf.
Slice the meat loaf and serve hot, with your favorite sides.