Prepare the thin spaghetti according to package directions.
Prepare the Alfredo sauce by placing heavy cream, garlic, salt and pepper in a medium sauce pan. Bring to a boil.
Add the cream cheese (cut it into small pieces first) and butter. Use a whisk to combine until smooth.
Just as the sauce begins to boil, add 2 cups Parmesan cheese. Use a whisk to stir until the cheese has melted and combined for a smooth Alfredo sauce.
Combine the spaghetti and Alfredo sauce in a large mixing bowl.
Spray a muffin tin with cooking spray and spoon the spaghetti/Alfredo mixture into each muffin cup. Pack down with a spoon and top with shredded mozzarella cheese. Sprinkle with oregano.
Bake in a 350 degree oven for 20-25 minutes, or until the cheese is melted and starting to get some golden spots.
Toward the end of baking, heat up marinara sauce and meatballs.
Prepare the dish for serving by spooning marinara sauce on a plate. Add one or more baked spaghetti rounds, and top with meatballs.