1. Bring a large pot of salted water to the boil. Cook penne per packet instructions (usually 11 min). Reserve 100ml pasta water before draining.
2. Meanwhile, finely dice the onion and mince the garlic. Heat olive oil in a wide pan over medium heat. Soften onion 5 minutes, then add garlic and chilli flakes. Cook 1 minute.
3. Add tinned tomatoes, oregano, sugar, salt and pepper. Simmer 10 minutes, breaking up tomatoes.
4. Stir in the drained pasta with a splash of pasta water to loosen. Toss well.
5. Slice the baguette, butter each piece, and grill or toast until golden.
6. Serve pasta topped with fresh basil and grated parmesan, with garlic bread alongside.