Top 12+ Secret Ingredients Grandma Used in Her Meatloaf
Hard Boiled Egg

Instead of putting an egg on it, put an egg in it! Place your meatloaf mixture onto a piece of plastic wrap and form it into a 8x12 rectangle. Place three peeled hard-boiled eggs in the center and roll the long end of the loaf over the eggs. Discard the wrap, place the log in your loaf pan and bake it like normal. When you slice into it, you'll get an eggy surprise!
Tomato Sauce and Italian Seasonings

Adding tomato sauce, tomato juice or marinara to your meatloaf can only make it more flavorful. Add in a sprinkling of Italian seasonigs—think basil and oregano.
Phyllo Dough or Puff Pastry

Most kids wouldn't eat something called Beef Wellington, but they'd totally eat a puff pastry-wrapped meatloaf. The wrapper itself adds a delicious texture to your plate while also keeping the juices sealed inside, creating the juiciest, most flavorful meatloaf imaginable.