How to Make It
Heat 3 tablespoons oil in a large skillet over medium. Add panko and cook, stirring constantly, until golden brown, about 2 minutes. Transfer to a bowl and stir in parsley, lemon zest, salt, and pepper. Wipe skillet clean.
Bring a large pot of salted water to a boil. Add spaghetti, return to a boil, and cook, stirring occasionally, until al dente, about 8 minutes.
During the last few minutes of pasta cook time, add remaining 2 tablespoons oil to skillet and heat over medium-high. Add shallot and garlic and cook, stirring often, until golden, about 2 minutes. Add sardines and cook, stirring often, for 1 minute.
Using tongs, transfer cooked pasta directly to skillet. Add 1 cup pasta water and cook, tossing constantly, until liquid reduces and coats pasta, 1 to 2 minutes. Add lemon juice and half the panko mixture and toss to combine.
Top with remaining panko mixture, drizzle with oil, and serve with lemon wedges.