Heat 1 tsp of oil in a frying pan and add the breadcrumbs, basil, parsley and a pinch of the crumbled chilli. Cook for 4-5 minutes until the breadcrumbs are crispy, then remove from the pan and set aside.
Add the rest of the oil to the pan and heat. Add the remaining crumbled chilli and garlic, and cook over a low heat for 5-6 minutes, until very fragrant, making sure the garlic doesn’t burn.
Stir in the onion and cook for another 3-4 minutes until beginning to soften. Add the tomatoes, sugar, red wine vinegar and whole chilli, then bring to the boil. Simmer gently for 8-10 minutes or until thickened slightly.
Meanwhile, cook the spaghetti according to pack instructions. Drain well, reserving 3 tbsp of the cooking water.
To serve, stir the reserved cooking water into the sauce, and then remove the whole chilli. Add the pasta to the sauce and toss through, then divide between four plates. Sprinkle over the herby breadcrumbs to serve.