Melt butter in a skillet over medium heat. Add the onion and garlic into the melted butter for 5 minutes, stirring occasionally until the onions become translucent.
Place mixture in a large bowl to cool for 5 minutes.
Combine turkey, bread crumbs, egg, 1/4 cup of the ketchup, Worcestershire sauce, salt, pepper, and lemon zest with onion mixture. Press meatloaf into a cupcake pan filling each cupcake spot with meatloaf mixture.
Spread remaining ketchup on top of each "cupcake". Bake at 350° for 25 minutes or until a thermometer registers 160°. Let stand for 5 minutes.
While the meatloaf is cooking you can start making the mashed potatoes. Place potatoes in a saucepan and cover with water. Bring them to a boil, cover and reduce heat to a simmer for 10 minutes or until tender.
Drain and return potato to pan.
Using a hand masher or a mixer smash the potatoes. Add milk and remaining ingredients and mix until desired consistency.
Place the turkey loaf into a cupcake liner.
Put the potatoes into a pastry bag or a freezer bag with a corner cup off with a wide star tip and pipe the mashed potatoes on top of the meatloaf.