Put a pan of water on to boil, then, when ready, add salt and your pasta. Cook as per the packet instructions until al dente. While your pasta is cooking, you can fry your bacon
In a bowl, whisk together the egg yolk, 40g of the parmesan and some black pepper. Add in the reserved pasta water to complete your sauce
Cut your bacon into small pieces, add back into your pan along with your sauce and your cooked pasta and mix to combine. The heat from the pasta will gently cook the eggs in the sauce - you don't want too high a heat or you'll end up with scrambled eggs
Plate up and sprinkle your remaining Parmesan on top - enjoy!