Heat white wine until steaming, then add raisins and saffron to soak.

Toast bread crumbs with fennel seed in olive oil and season.

Boil salted water for pasta. Mince fennel fronds.

Sauté onion and fennel bulb in olive oil until tender, then add anchovies until dissolved.

Add wine, raisins, and saffron mixture to the pan, scraping up any browned bits.

Add pine nuts and sardines and cook until sardines are cooked through.

Cook pasta until al dente, reserving pasta water.

Transfer pasta to skillet, add pasta water, and cook until sauce coats the pasta.

Drizzle olive oil and minced fennel fronds, and toss. Season with salt.

Add bread crumbs and toss. Add more pasta water or olive oil if needed.

Divide pasta into bowls, distributing sardines, pine nuts, and raisins evenly. Top with bread crumbs and garnish with fennel fronds.