Boil pasta to al dente.  Reserve 1/2 cup pasta water (plus some extra in case you want it).  Drain the pasta.

Meanwhile, in a small bowl combine the egg yolks with grated cheese. 

In a skillet, sauté the bacon until it is crispy and has rendered fat in the pan. 

Add the onions, and garlic, and sauté until soft and transparent, about 3-5 minutes. 

Add the drained chopped clams (reserving clam juice for another use) and cooked pasta.  Cook while stirring for another 1-2 minutes.

Remove the skillet from the heat.  Slowly add the egg mixture while stirring constantly. 

Add 1/2 hot (but not boiling) pasta water and chopped parsley.  Season with salt and pepper to taste.  Add more pasta water if you would like a thinner sauce.

Serve with more grated parmesan and pepper at the table.