Preheat oven to 400 degrees F. Spray a standard 12-cup muffin pan with cooking spray and set aside.
Place meat in a large bowl. Add zucchini, onion, egg, breadcrumbs, salt, pepper, and 2 tablespoons of the ketchup. Use your hands to gently combine. You don’t want to over-mix because the meat will become dry and tough.
Press the ingredients into the prepared muffin cups. I like to use an ice cream scoop to portion the meat into each cup. Top each mini meatloaf with a dollop of the remaining ketchup.
Place the muffin pan on a foil-lined baking sheet (to catch any drips).
Bake for 20-25 minutes, or until meatloaves are cooked through and a thermometer registers 160 degrees F.
Notes
To prepare a single large meatloaf (rather than the mini meatloaves), simply shape the meat mixture into the shape of a loaf. Place on a rimmed baking sheet that has been lined with foil and sprayed with cooking spray. Bake at 350 degrees F for about 45 minutes, or until the meatloaf reaches an internal temperature of 160 degrees F.To freeze, cool the loaves to room temperature, wrap them individually in plastic wrap, and freeze them in a resealable plastic bag. To reheat, simply remove the plastic and bake them on foil-lined baking sheet that has been sprayed with cooking spray. You can bake them directly from the freezer (still frozen). It should take about 20 minutes in a 350-degree F oven for the mini meatloaf to warm through.