Preheat oven to 375°. Lightly spray a 13x9-inch baking dish with cooking spray.
In a large Dutch oven, heat oil over medium heat. Add garlic and fennel seeds; cook, stirring constantly, for 1 minute. Stir in pasta sauce, ¼ cup basil, and tomato paste; cook, stirring frequently, for 10 to 15 minutes.
In a medium bowl, stir together ricotta, roasted peppers, Parmesan, eggs, salt, and remaining ½ cup basil.
Spread 1 cup tomato sauce in bottom of prepared pan. Layer with half of cooked pasta, half of remaining tomato sauce, all ricotta mixture, remaining pasta, all meatballs, and remaining sauce. Cover with foil.
Bake for 30 minutes. Uncover casserole, and sprinkle with mozzarella. Bake until melted, about 10 minutes more. Let stand for 15 minutes before serving. Garnish with basil, if desired.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/meatball-casserole-recipe/