Preheat oven to 350F.

Line a standard muffin pan with silicone or paper wrappers. Set aside.

Place the ground beef in a large bowl and add in the egg yolks, Worcestershire sauce, seasoning and milk. Combine.

Add onion, garlic and breadcrumbs, mixing until completely cohesive and all ingredients are incorporated.

You want the meat mixture to hold it's shape while being soft to the touch. Add additional milk or breadcrumbs to achieve the ideal texture.

Divide the meat mixture into 12, placing about 1/4 cup of the mixture into each prepared muffin liner.

Bake the meatloaf cupcakes for 25-30 minutes, until an inserted meat thermometer reaches at minimum 160F.

About 8-10 minutes before the end of the cooking time, combine together the ketchup and brown sugar and remove the meatloaf cupcakes from the oven. 

Brush the ketchup mixture onto the top of each cupcake and then return the pan to the oven for the remaining time.

While the cupcakes are baking, prepare your mashed potatoes according to your personal preferences.

Allow the potatoes to cool slightly, then transfer into a piping bag fit with a large star tip.

When the meatloaf cupcakes are done baking and have cooled for a couple minutes, swirl the mashed potato "frosting" onto each one.