Cook the spaghetti in boiling salted water for about 11 minutes. Wash parsley, dab dry and chop finely. Grate 50 g Parmesan finely. Cut bacon into strips. Leave it crispy in a pot.
Peel garlic, dice finely and fry briefly. Whisk cream, egg yolk, parsley and parmesan, season with salt and pepper. Add to the bacon and remove from the heat immediately. Drain spaghetti and let it drain.
Put it back in the pot. Add the cream-egg mixture and mix with the noodles. Slice 25 g parmesan and sprinkle over the pasta. Serve immediately.