Cut the cauliflower into medium-sized pieces. Peel and finely chop 1 large clove of garlic. Strip the leaves from the thyme.
Cook the spaghetti in salted water in a large saucepan for 5 minutes. Add the cauliflower and cook for another 5 - 7 minutes until the cauliflower is tender.
Meanwhile, heat the oil in a pan and fry the garlic, breadcrumbs, hazelnuts, raisins and thyme leaves for 3 - 4 minutes. Stir frequently until everything is golden and crispy. Take off the stove and keep warm.
Drain the spaghetti and cauliflower and return to the saucepan. Mix with the breadcrumb mixture and season to taste. Serve immediately. Broccoli can also be used instead of cauliflower.