Preparation Cook spaghetti in a pasta pot of well- salted boiling water until al dente. Meanwhile, heat oil in a 12-inch heavy skillet over medium heat until it shimmers. Fry capers until they "bloom" and are just a shade darker, about 2 minutes. Transfer with a slotted spoon to paper towels to drain. Toast bread crumbs in same skillet, stirring, until golden, about 3 minutes. Transfer to a bowl and toss with capers, dill, and 1/4 teaspoon each of salt and pepper. Add sardines to skillet with their oil (if using 3 cans sardines, discard oil from 1 can) over medium-high heat, then force garlic through a garlic press into skillet. Sauté until sardines are golden in spots around edges, about 2 minutes. Reserve 1 cup pasta-cooking water, then drain pasta. Add pasta to skillet with cooking water and 1/2 teaspoon each of salt and pepper. Toss until pasta is coated and sauce is slightly thickened, 1 to 2 minutes. Serve topped with seasoned crumbs.