Heat 2 tablespoons olive oil in a 10-inch sauté pan over medium heat until shimmering.
Add the finely chopped 1/2 medium onion and sauté for about 1 minute, stirring occasionally.
Add the minced 2 garlic cloves and a pinch of red pepper flakes and continue to sauté until the onion is soft and translucent, about 4 more minutes.
Stir in the 28 oz crushed tomatoes, 1/2 teaspoon dried oregano, 1/2 teaspoon sugar, a few pinches of kosher salt and several turns of freshly ground black pepper; bring to a boil.
Reduce heat to low, partially cover, and simmer the sauce for 30 minutes, stirring occasionally.
Stir in 1 tablespoon chopped parsley and 1 tablespoon chopped basil, then taste and adjust seasoning with salt and pepper as needed.
Meanwhile, bring a large pot of salted water to a boil and cook the 16 oz gnocchi according to package instructions until they float; drain well.
Transfer the cooked gnocchi to the pan with the tomato sauce and stir to coat evenly.
Top the sauced gnocchi with the torn 6 ounces fresh mozzarella and a generous sprinkling of freshly grated Parmesan.
Place the pan under a high broiler and cook 5 to 7 minutes, until the cheese melts and is golden and slightly crisp in spots.
Remove the pan from the oven, fold the melted cheese into the gnocchi, sprinkle with additional parsley and basil, and serve immediately.
