1 small yellow onion, minced
2 eggs, beaten
1 cup uncooked old-fashioned oats (not quick cooking)
1/4 cup pitted prunes, very finely chopped
1 5.5-ounce can tomato juice
2 tablespoons prepared horseradish sauce
1/2 teaspoon kosher salt
1 teaspoon dry mustard
1 1/2 pounds lean ground beef (at least 92 percent lean)
1/2 pound ground pork
3 tablespoons ketchup
3 pounds Yukon gold potatoes, peeled and cut into 2-inch pieces
3 tablespoons butter
scant 1/2 cup whole milk
8 ounces cream cheese, cut into chunks
Preheat oven to 350 degrees F. In a large bowl, combine the onion, oats, eggs, tomato juice, prunes, horseradish sauce, salt and dry mustard and mix well. Add the beef and pork and mix until just combined.
Divide the mixture between nine jumbo or 18 standard muffin cups and level off the top so that each cupcake is flush with the top of the pan. Top each cupcake with one teaspoon ketchup and spread evenly with the back of a spoon.
Bake cupcakes for 30 to 35 minutes, or until a meat thermometer reaches 155 degrees F.
Meanwhile, boil the potatoes in salted water until easily pierced with a fork, about 25 minutes; drain and return to the pot. Toss potatoes over low heat for 2-3 minutes to evaporate any moisture then remove from heat & begin to mash with a potato masher.
Once there are no large chunks, transfer the potatoes to a mixer with a whisk attachment.
In a small saucepan, combine the butter and milk. Warm over medium-low heat until butter is melted and milk is hot but not boiling.
With the mixer running, very carefully pour the warm milk mixture down the side of the mixing bowl of potatoes; whip until the liquid is incorporated.
Add the cream cheese, a few pieces at a time, mixing after each addition. Season to taste with salt. Spoon mashed potatoes into a pastry bag with a wide round tip (or use a large plastic bag with one corner snipped off).
When meatloaf cupcakes are cool enough to handle, gently drop each one into a paper cupcake liner. Pipe the mashed potato “frosting” onto each cupcake and serve to unsuspecting family members!