Preheat the oven to 425°F, and if possible place an empty sheet pan inside while it heats.
In a bowl, mix the panko and milk, then let it sit for 2 to 3 minutes to form a quick panade.
Stir in the onion, garlic, Worcestershire sauce, ketchup, salt, pepper, paprika, and parsley.
Add the ground beef and egg, then mix just until combined without overworking the meat.
Shape the mixture into 8 mini meatloaves about 1 to 1 1/2 inches thick, and place them on a rack over a sheet pan or on parchment.
Bake at 425°F for 10 minutes, then reduce the heat to 400°F and bake 8 to 15 minutes more, until the internal temperature reaches 155°F for beef so it can rest to 160°F.
While the meatloaves bake, stir together the glaze ingredients.
Brush the glaze on during the last 5 to 7 minutes of baking.
Rest the meatloaves for 5 minutes before serving.