2 tablespoons walnut pieces or chopped pecans to decorate
2 x 20.5cm sandwich tins, greased and base-lined
Heat the oven to 180C/350F/Gas 4. Put the eggs and sugar into the bowl of a food mixer and beat, with the whisk attachment, until very light and frothy. Gradually beat in the oil. Using a large metal spoon, stir in the carrots. Sift the flour, cocoa, baking powder, cinnamon and ginger into the bowl and stir in. Once thoroughly combined mix in the nuts.
Transfer the mixture to the prepared tins, dividing it evenly. Bake in the heated oven for 25 minutes or until firm to the touch. Turn out the sponges on to a wire rack and leave to cool completely.
Meanwhile, make the filling and topping: put the soft butter, cream cheese, vanilla, icing sugar and cocoa into the bowl of a food mixer and beat, on low speed, until very smooth and creamy.
Use about half to sandwich the sponges, then spread the rest on top. Scatter over the nuts. The cake will taste at its best if kept for a day before cutting. Store in an airtight container and eat within 5 days.