Whisk together the egg yolks and sugar
until thick and creamy. Stir in the carrots, nuts and lemon rind, then
fold in the flour and baking powder. Whisk the egg whites until they
form soft peaks, then fold into the mixture. Turn into a greased 19
cm/7 in square cake tin (pan). Bake in a preheated oven at
180°C/350°F/gas mark 4 for 40-45 minutes until a skewer inserted into
the center comes out clean.