Instructions

1. Arrange 2 racks to divide the oven into thirds and heat the oven to 425ºF. Line 2 rimmed baking sheets with parchment paper or aluminum foil.
2. Place 2 cups bread stuffing in a large bowl. (If your stuffing is chunky, place it in a food processor fitted with the blade attachment and pulse until the pieces are no larger than a pea first.) Finely grate 2 ounces Parmesan cheese (about 1/2 cup) and add to the bowl.
3. Add 1/4 cup tomato paste, 2 large eggs, 1 tablespoon Italian seasoning, 1 teaspoon garlic powder, 3/4 teaspoon kosher salt, and 2 pinches red pepper flakes if desired. Mix with a wooden spoon or your hands until the mixture is well blended.
4. Add 1 pound ground beef and 1 pound ground pork and mix with the wooden spoon until blended. Do not over-stir or the meatballs will become tough. Form the meat mixture into 50 walnut-sized meatballs (about 2 tablespoons each), and place on the prepared baking sheets, spacing them at least 1 inch apart so they brown evenly.
5. Bake, rotating the baking sheets halfway through, until the meatballs are just cooked through, about 15 minutes total. (An instant-read thermometer will register 160ºF when inserted into the center of a meatball.) Meanwhile, coarsely chop 1/4 cup fresh basil leaves.
6. Pour 1 (about 24-ounce) jar marinara sauce into a large saucepan, then add half of the meatballs. Cover and simmer over medium-low heat, stirring occasionally, until the sauce is heated through, about 5 minutes. Top with the basil and serve over pasta, soft polenta, or mashed potatoes.