Mix the grated hazelnuts and walnuts well with the cocoa. Grate the zucchini very finely and squeeze well, in any case there should be a total of 350 g of zucchini grated for the dough.
Beat the eggs with sukrin until foamy. Then mix in the vanilla and zucchini, then carefully incorporate the nut-cocoa mixture. You should get a rather runny but airy dough.
Pour the batter into a springform pan lined with baking paper and bake at 180 °C for about 40 minutes.
If the cake threatens to get too dark, cover with aluminum foil in time.
Test with a chopstick and bake a little longer if necessary.