Olive Garden makes a similar dish except their version is topped with cheese and baked until bubbly and hot. If you want to try their approach, I would assemble as directed, then pour the pasta and alfredo sauce into an oven-safe baking dish and sprinkle with 1/2 to 1 cup of mozzarella cheese, then broil for 3-5 minutes or bake for 15 minutes at 350 degrees F until bubbly before serving.