Meatloaf Cupcakes with Whipped Potato Topping

Oven Preparation: Commence by preheating your oven to a temperature of 375 degrees Fahrenheit (190 degrees Celsius). Prepare a standard muffin pan by lightly coating it with nonstick spray to facilitate the easy release of the meatloaf cupcakes once baked.
Mixing of Ingredients: In a capacious mixing bowl, amalgamate the ground beef, sweet yellow onion, both types of bread crumbs, tomato sauce, beaten eggs, Worcestershire sauce, minced garlic, parsley flakes, kosher salt, black pepper, and ground mustard seed. Employ a sturdy wooden spoon or gloved hands to ensure thorough integration of all ingredients, achieving a homogeneous mixture.
Filling the Muffin Pan: Employing a 3-tablespoon cookie scoop or a similar utensil, distribute the meat mixture evenly into the cavities of the prepared muffin pan. Each cup should be filled to just below the rim to accommodate slight expansion during the baking process.
Applying the Glaze: Prior to baking, top each filled muffin cup with a teaspoon of ketchup, spreading it across the surface to create a glaze that will caramelize during baking.
Baking: Insert the muffin pan into the preheated oven and bake for a duration of 30 minutes, or until the meatloaf cupcakes are thoroughly cooked and exhibit a rich, golden hue on their surfaces.