Preheat the oven to 350 degrees F. Bring a large pot of water to a boil. Add the ravioli and cook according to package directions. Drain and set aside. Meanwhile, heat the olive oil in a medium pot over medium heat. Add the garlic and cook until fragrant, about 30 seconds. Crush the tomatoes with your hands and add them along with all the juices from the can to the pot. Add the whole sprig of basil, 3/4 teaspoon salt and pepper to taste. Cook, simmering, until the tomatoes are softened and the sauce is thickened slightly, about 15 minutes. Remove from the heat, season with the sugar and additional salt and pepper.
In a medium bowl, mix the ricotta cheese with the Parmesan, egg, torn basil and 1/4 teaspoon each salt and pepper.
Lightly mist a medium rectangular or oval baking dish (about 9-by-11-inch) with nonstick cooking spray. Lay half the ravioli in the bottom of the dish (the ravioli will be layered on top of each other). Remove the sprig of basil from the sauce. Spread half the ricotta mixture over the ravioli and top with half the sauce and half the grated cheese. Repeat with the remaining ravioli, ricotta and sauce. Cover with aluminum foil and bake until bubbly, about 45 minutes. Remove the foil and sprinkle with the remaining cheese. Continue to bake until the cheese is melted, about 10 minutes. Let stand at least 10 minutes. Garnish with extra torn basil. Slice and serve with a green salad.