Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the minced garlic and 1/4 teaspoon red pepper flakes (if using) and cook for 30 seconds until fragrant, being careful not to burn the garlic.

Add the Panko breadcrumbs to the skillet. Cook, stirring frequently, for 5-7 minutes until they are golden brown and crispy. Season with a pinch of salt. Transfer the breadcrumbs to a small bowl and set aside.

Bring a large pot of salted water to a rolling boil. Add the spaghetti or linguine and cook according to package directions until al dente. Before draining, reserve about 1 cup of the starchy pasta water.

While the pasta is cooking, wipe out the same large skillet (or use a fresh one). Heat 3 tablespoons of extra virgin olive oil over medium-low heat. Add the thinly sliced garlic and the remaining 1/2 teaspoon of red pepper flakes. Sauté gently for 1-2 minutes until fragrant, without browning the garlic.

Add the drained anchovy fillets to the skillet. Using a wooden spoon or spatula, mash the anchovies into the oil until they dissolve and form a pungent, salty paste. This should take 2-3 minutes.

Using tongs, transfer the cooked pasta directly from the pot to the skillet with the anchovy sauce. Add about 1/4 cup of the reserved pasta water. Toss vigorously to coat the pasta in the sauce, allowing the sauce to emulsify and cling to the noodles. Add more pasta water, a tablespoon at a time, if the sauce seems too dry.

Remove from heat. Stir in the lemon zest and chopped fresh parsley. Season with freshly ground black pepper to taste. The anchovies are salty, so taste before adding any more salt.

Divide the pasta among serving bowls and generously top each portion with the crispy garlic breadcrumbs. Garnish with additional fresh parsley if desired. Serve immediately.