Soak the spaghetti noodles in water for about 10 minutes.
Place the noodles, milk, heavy cream, salt, and pepper in a microwave-safe container.
Finely chop the bacon, onion, and garlic, and add them to the container.
Cover with a lid or plastic wrap and microwave at 700W for 6–7 minutes.
Stir the noodles to check if they are cooked; if necessary, microwave for another 1–2 minutes.
Sprinkle with Parmesan cheese and parsley to finish.