Cook the pasta in salted water until al dente and in the meantime wash the lemon with hot water and rub dry. Use the zest peeler for decoration, peel off some zest, finely grate the remaining peel and squeeze out the juice.
Heat the oil in a large pan and fry the zucchini pieces in it. Take out of the pan. Now put the onion and garlic cubes in the pan and sauté. Put the zucchini cubes with the tomato cubes and 1 tablespoon lemon zest in the pan. Season with salt and pepper and let simmer for approx. 2 minutes. Season to taste with lemon juice.
Drain the pasta, but do not let it drain completely. Pour into the pan and carefully mix everything together. Season with salt, pepper and cayenne pepper. Garnish with parsley and the lemon zest.