1. Preheat oven to 190°C/375°F/Gas 5. Grease and base line a 23cms/9" square tin. 2. Put the eggs, oil and sugar into a mixing bowl and beat until well blended. Add the carrot and mix well. 3. Next, stir in the flour, bread soda (sieved) and spices. Finally mix in the 60g walnuts. 4. Transfer to the prepared tin and spread evenly. Bake in the centre of the oven for 30-40 minutes until nicely risen and firm to the touch. 5. Remove from the oven and allow to get cold in the tin, then, turn onto a wire tray. 6. Make the topping by putting the cream cheese, butter and icing sugar into a bowl and beat until really smooth. 7. When cake is completely cold, spread with the topping, smooth over with a fork and leave to set. Cut into squares and sprinkle the remaining walnuts on top of each square.