Prep all ingredients according to specifications above.
Prepare Lemon Bottarga Breadcrumbs: Heat oil in small skillet over medium-low heat. Add breadcrumbs, black pepper and salt and cook until breadcrumbs are toasted, about 2 to 3 minutes, stirring continuously. Fold in bottarga and lemon zest and mix well. Remove from heat and set aside, uncovered, at room temperature.
Bring a large pot of water to a boil to cook the pasta. Use only about 3 quarts water. (See NOTE below.)
Meanwhile, melt 4 Tbsp butter in a large skillet or Dutch oven over medium-low heat, then add the anchovies and its residual oil, garlic and crushed red pepper. Stir and cook for about 3 to 4 minutes until the anchovies have mostly dissolved, then add half the parsley and cook for 2 more minutes.
Add the wine and stir to loosen and scrape up any browned bits on bottom of pot. Simmer for 3 to 4 minutes or until the alcohol taste has cooked off. Stir in 2 Tbsp colatura, then set aside on low heat.
Once the pasta water comes to a boil, add the fettuccine, stirring frequently. Cook the pasta for 2 minutes less than the package directions, or about 2 minutes before you think it is al dente. Be sure to reserve at least 1 cup of the starchy pasta water.
Transfer the cooked pasta and about ¾ cup pasta water to the pan with the sauce and increase the heat to medium. Toss well, allowing the pasta to finish cooking in the delicious flavors of the sauce. Add additional pasta water if more moisture is needed.
Turn off the heat. Add the remaining 2 Tbsp butter, ½ cup parsley and 1 Tbsp colatura and stir. Then quickly mix in the egg yolks and continue to toss until all ingredients are well-combined and the pasta has been well-coated with the egg. Fold in half the lemon bottarga breadcrumbs.
Adjust seasonings with additional salt and black pepper if necessary. Transfer to a serving platter or bowl and top each plated serving with additional breadcrumbs. Buon Appetito!