Heat the oven to 375°F (190°C) and line a baking sheet with parchment. If using frozen bread dough instead of refrigerated pizza dough, thaw it according to the package directions.

Roll the dough into an approximately 12 x 15-inch rectangle and transfer it to the prepared baking sheet. Spread 1/2 cup sauce down the center third, leaving the top, bottom, and side borders clear.

Arrange the thawed, well-drained meatballs over the sauce. Sprinkle with mozzarella, Parmesan, Italian seasoning, and optional garlic.

Cut diagonal strips about 1 inch apart along both sides of the filling. Fold the strips over the meatballs, alternating sides, then pinch or tuck the ends closed.

Brush the exposed dough with beaten egg and add a little extra Italian seasoning or Parmesan if desired. Bake for 25–30 minutes, until deeply golden, fully baked, and hot in the center; a bread-baking thermometer should read roughly 190–200°F (88–93°C).

Let the braid rest for 5–10 minutes before slicing. Garnish with parsley or Parmesan and serve with warmed marinara sauce.