Preheat the oven to 180°C, fan 160°C, gas mark 4. In a small bowl, mix together the tartare sauce, soft cheese and half the rosemary until well combined. Set aside.
In another small bowl, combine the breadcrumbs, lemon zest and the remaining chopped rosemary.
Drizzle the olive oil into a shallow baking tray and lay the salmon fillets on top.
Spread a thick layer of the cream cheese mixture onto each fillet, then top with the breadcrumb mixture.
Bake in the oven for 20-25 minutes, until the breadcrumbs are golden and the salmon is fully cooked through.