Put the tomatoes in a roasting tin, drizzle over the oil and sprinkle with the garlic, the torn leaves from 3 rosemary stems, paprika or chilli powder and a little seasoning. Cook in a preheated oven, 200°C (400°F), Gas Mark 6, for 15 minutes or until just softened.
Meanwhile, cook the pasta in a large saucepan of boiling water for 10—12 minutes or until just tender, then drain.
Spoon the balsamic vinegar into the tomatoes, add the drained pasta and crème fraîche or ricotta and toss together. Spoon the penne into bowls and top with Parmesan shavings.