Gooey Cheesy Meatballs
1 slice bread
1/4 cup milk
1 pound ground beef
1 small onion, grated
1 tablespoon sour cream
1 large egg
1/2 teaspoon salt
1/2 teaspoon ground black pepper
1/4 cup mayonnaise
3/4 cup shredded mozzarella cheese
1/4 cup grated Parmesan
Preheat the oven to 400 degrees F. Line a baking sheet with foil; then lightly coat the foil with nonstick spray.
In the bowl of a food processor, pulse the bread until they resemble crumbs.
Heat a small skillet over medium heat. Add the bread crumbs and toast until golden brown, about 4-5 minutes.
In a small bowl, combine the toasted bread crumbs and milk; let stand until all of the milk is absorbed.
In a large bowl, add the breadcrumb mixture, ground beef, grated onion, sour cream, egg, salt and pepper.
Using a wooden spoon or clean hands, stir until well combined.
Roll the mixture into 1 1/4-to-1 1/2-inch meatballs and place on onto prepared baking sheet. (I used a small cookie scoop for this.)
Drizzle a small amount of mayonnaise on each meatball. (A squeeze bottle or Ziploc bag is perfect for this.)
In a small bowl, combine the mozzarella and Parmesan. Sprinkle each meatball with 1 tablespoon cheese mixture.
Place into oven and bake until the cheese has melted and is slightly golden brown, about 15-20 minutes. Broil for an additional 2-5 minutes, or until the cheese has crisped up.