Finely dice bacon and onion, pluck thyme from stems. Mix eggs, whipping cream, thyme and 2/3 of the Parmesan. Season with salt and pepper.
Cook spaghetti al dente according to package directions.
Heat oil in a frying pan, fry bacon until crispy. Add onion and sauté. Remove half of the bacon.
Drain the spaghetti and add to the frying pan.
Remove skillet from heat. Stir in egg and cream mixture and cook until slightly stiff.
Arrange the pasta on plates. Sprinkle with the remaining bacon as well as the cheese.