Wash the zucchini, pat dry the base of the stem and cut off the tip, then rub it roughly on a large grater. Peel the onion and chop finely. Mix the remaining ingredients well with a hand mixer and then stir in the zucchini with the onions.
Put the mixture in a well-greased springform pan (28 cm diameter), smooth it out and bake in a preheated oven at 200 ° C (top / bottom heat) for about 1 hour. The cake should get a golden brown crust. A mixed salad goes well with it.