For the carrot cake, first beat the egg whites until stiff. Fold in the sugar.
Finely grate the nuts and carrots. Fold the nuts, the carrots and the baking powder into the egg whites. Finally, carefully mix in the egg yolks.
Place the sponge cake on the spot in a greased cake springform pan lined with parchment paper. Bake the carrot cake at 180 °C (gas mark 3) for about 45 minutes.