Preheat oven to 350 degrees. In a medium to large saucepan, combine the pasta sauce and frozen meatballs. Cook over medium heat until warmed completely through, about 10-15 minutes, stirring so meatballs don’t stick to pan. While meatballs are cooking, cut baguette into approximately 12 slices (enough to go around the edge of your baking dish.) Combine garlic and olive oil and brush over slices of bread. Place meatballs in the center of a 9x12 baking dish. Sprinkle mozzarella, Italian blend cheese and Parmesan over top of meatballs Line the pan all the way around with bread slices, (standing up) pressing them slightly into the meatball mixture. If desired, sprinkle the bread lightly with any remaining cheese. Bake for about 20 minutes or until cheese is melted and bubbly and bread has toasted to a golden brown. Serve as a side or as a main dish with vegetables or a salad. Casserole can be made ahead and heated in the oven when ready to serve.