Cook the spaghetti in a large saucepan of boiling, salted water for 8-10 minutes until 'al dente'.
Meanwhile, heat the extra-virgin olive oil gently in a saucepan over a medium heat. Add most of the sundried tomatoes, passata, caster sugar and seasoning. Cook gently for a few minutes then transfer to a food processor and purée until smooth.
Adjust the seasoning to taste, then spoon back into a saucepan. Add the remaining sundried tomatoes and keep over a very low heat. Drain the spaghetti when it is ready and toss with a little bit of the sundried tomato purée. Spoon into serving bowls and top with more of the purée.
Garnish with the sliced basil, parmesan shavings and basil leaves before serving.