Cook the farfalle following pack instructions. Meanwhile, heat the oil in a non-stick frying pan over medium heat. Add the garlic and onion and saute until softened. Add the sausage and fry briskly for 5 minutes, stirring constantly. Pour over the wine, bring to the boil and simmer for 5 minutes, enough for the sausage meat to lose its raw color. Add the zucchini and cook until softened. Pour the cream and bring to the boil. Decrease the heat to low and gently simmer for 2-3 minutes, until thickened slightly. Season with salt, sugar and pepper.