In a small sauté pan over medium-high heat, toast the bread crumbs in dry pan until just golden brown, stirring continuously to avoid burning. Transfer to a bowl and stir in the red pepper flakes and 2 tablespoons of olive oil and set aside.

In a medium sauté pan, heat ¼ cup of olive oil over medium heat. To the hot oil add the chopped fennel, onion, garlic and season with salt and pepper. Cook, occasionally stirring, until the fennel is softened, about 20 minutes. Add the white wine, raisins, and the sardines. Bring to a boil then reduce to a gentle simmer for about 10 minutes and the sardines are easy to break apart with a fork.

Remove pan from the heat.

In a large stock pot bring 6 quarts of salted water to a boil. Add the perciatelli and cook until al dente, 6-7 minutes, strain, reserving ½ cup of the cooking liquid. Return the pasta to the pot along with the reserved cooking liquid. Fold in the cooked fennel and sardines and season with salt and pepper to taste. Drizzle 3 tablespoons extra virgin olive oil and stir in half of the reserved fennel fronds, capers and pignoli nuts and 1 tablespoon of the toasted bread crumbs.

Divide the pasta among 4 plates and sprinkle the remaining fennel fronds and bread crumbs overtop and serve right away.