Grease and line the bottom and sides of a deep 20cm round or square cake tin. Beat the butter and sugar until light. Add the egg yolks, then stir in the orange rind.
Sift the self-raising flour, baking powder and spices. Fold into the butter mixture along with the nuts.
Beat the egg whites in a separate bowl until stiff, then fold into the mixture, along with the grated carrots and raisins.
Spoon into the prepared tin and make a hollow in the middle of the cake with the back of a spoon. Bake in a preheated oven for 1 and a quarter to 1 and a half hours
until a skewer comes out clean.
If the top of the cake becomes dark after 45 minutes, cover with aluminium foil.Remove from the oven and leave to
cool in the tin for 15 minutes before
turning out. Leave to cool completely
on a wire rack.
Beat the butter until creamy. Add the cream cheese and beat until smooth, then stir in the sifted icing sugar. Refrigerate until firm. Remove from the fridge and allow to soften slightly.Spread over the top and sides of the cake, then spoon the remaining icing into a piping bag with a star nozzle. Pipe around the edges of the cake to decorate, and sprinkle
chopped nuts over the top.