Preheat your oven to 350°F (175°C) and lightly grease the muffin tin.
In a large mixing bowl, combine the ground beef, breadcrumbs, milk, ketchup, chopped onion, minced garlic, egg, Worcestershire sauce, Italian herbs, salt, and pepper. Mix until well blended.
Divide the meat mixture evenly among the muffin cups, filling each cup about three-quarters full.
Bake the meatloaf muffins in the preheated oven for 25-30 minutes, or until fully cooked (internal temperature should reach 160°F/70°C).
While the muffins are baking, prepare the mashed potatoes. Boil the cubed potatoes in a pot of salted water until tender, about 15 minutes.
Drain the potatoes and return them to the pot. Add the milk, butter, salt, and pepper. Mash until smooth and creamy. Adjust the milk for your desired consistency.
Once the meatloaf muffins are done, let them cool slightly before removing them from the muffin tin.
Using a piping bag or a spoon, top each meatloaf muffin with the mashed potatoes to resemble frosting.
Garnish with chopped chives or parsley if desired.