Preheat the oven to 375°F and lightly grease a loaf pan.
In a large bowl, combine the ground beef, breadcrumbs, egg, minced onion, garlic, salt, pepper, and 1 tablespoon of the brown sugar. Mix with your hands until just combined.
Press the mixture evenly into the prepared loaf pan.
In a small bowl, stir together the pomegranate molasses, remaining 2 tablespoons brown sugar, and apple cider vinegar until smooth.
Spread half the glaze over the top of the meatloaf.
Bake for 35 minutes, then remove from the oven and spread the remaining glaze on top.
Return to the oven and bake 15 minutes more, until the internal temperature reaches 160°F.
Let the meatloaf rest 5 minutes before slicing. Sprinkle with chopped parsley before serving.