Heat 250ml tub crème fraîche in a pan, stir in the tomatoes and other ingredients except for the oil. Toss with the cooked pasta.
Boil the pasta according to pack instructions. Meanwhile, roughly chop the tomatoes. Drain the spaghetti, reserving a cupful of the cooking water in the bottom of the pan.
With the pan still on the heat, stir the tomatoes, tomato purée, olives, oil and half the cheese into the water and bring to the boil. Simmer for a few mins to make a loose sauce, then season to taste. Toss the pasta and pine nuts through the sauce and serve sprinkled with the rest of the cheese.