Bring a large pot of generously salted water to a rolling boil. Slip in the spaghetti, stir once. Set a timer for 2 minutes less than the packet instructions.
Meanwhile, toast the panko breadcrumbs in 1 tbsp of the olive oil in a small pan over medium heat for 3 minutes until golden. Set aside.
In a wide pan over the lowest gas heat, warm the remaining olive oil with the sliced garlic, anchovies and chilli flakes. Stir gently, mashing the anchovies into the oil. Cook 2 to 3 minutes until the garlic is pale gold and the anchovies have dissolved.
When the pasta has 2 minutes left, lift it directly from the water into the sauce pan with tongs. Add a generous half-cup of the pasta water.
Toss over medium heat for 1 to 2 minutes until the sauce emulsifies into a creamy gloss that clings to the noodles. Add more pasta water if it looks dry.
Off the heat, fold through the chopped parsley and a generous squeeze of lemon. Taste; adjust salt and chilli.
Divide between bowls. Top with the toasted breadcrumbs and a drift of grated parmesan. Serve immediately.