Preheat the oven to 350? and grease a 9x13” baking dish.
Bring a large pot of water to a boil and add the spaghetti noodles. Cook the noodles per the package directions until they are “al dente”. Tip: the noodles should be fairly firm since they are going to cook longer in the oven. If they are boiled too long, they will not hold up well. Once the noodles are cooked, drain them and return them to the pot. Pour the jar of alfredo sauce over the noodles and mix until the noodles are coated. Set the noodles aside for later.
Brown and crumble the sausage in a large skillet over medium heat until the sausage has cooked through.
Drain any excess grease from the sausage and then add the garlic and onion to the pan. Cook for three minutes and then remove from heat
Add the jar of spaghetti sauce, Italian seasoning, and parsley flakes to the meat and stir to combine.
In a large bowl, mix together the cream cheese, ricotta cheese, parmesan cheese, and sour cream.
Assemble the layers: 1. Add half of the alfredo spaghetti noodles to the bottom of the 9x13” baking dish in an even layer. 2. Spread the cream cheese mixture in an even layer over the spaghetti noodles. 3. Add the remaining half of the alfredo spaghetti noodles over the cream cheese mixture in an even layer. 4. Spread the meat mixture in an even layer over the spaghetti noodles. 5. Sprinkle the mozzarella cheese over the top of the meat layer. Bake in the oven for 30-40 minutes or until the cheese is melted and the liquids are bubbling.
Remove from the oven and let sit for about 15 minutes before cutting into to preserve the layers. Or you can serve right away, but the layers may not be as defined. Optional: Top with fresh, chopped basil before serving.