Beat the egg whites until stiff and chill. Grate the carrots and mix the dry ingredients together. Mix the egg yolk, sweetener, orange peel and liqueur and carrots together. Then work the dry ingredients underneath. Finally, fold in the egg whites. Pour the dough into the baking pan and bake for about 60-70 minutes.
If you want, you can coat the cooled cake with chocolate icing and decorate with marzipan carrots. It is best when it can pull through for 1-2 days.