Kenwood Food processor fitted with the knife blade.
Preheat the oven to 180°C / 350°F / Gas 4. Grease a 24cm round, deep cake tin and line with baking parchment.
Place the carrots, stem ginger, sugar syrup and 2 tbsp water in the bowl of the Kenwood food processor with the knife blade fitted and process until the mix are a pulp. Empty the mix into a clean bowl.
You do not have to clean the food processor bowl, just add the butter, sugar and orange zest and process until pale and fluffy. Add the eggs, a little at a time. If the mixture separates, add a little flour. Add the flour, baking powder and cinnamon and pulse on a low speed until combined. Add the almonds, carrot pulp, and 75g walnuts, and process gently together until evenly combined.
Spoon the mixture into the tin, level off and bake for about 1-1¼ hours until risen and golden. To test the cake is cooked, push a skewer into the centre - it should come out clean. Remove from the tin and leave to cool on a wire rack.
To make the frosting:
Place the remaining walnuts into the small processing bowl (if supplied) and pulse until roughly chopped.
Spoon the cream cheese into the large food processing bowl, add the juice from the orange and icing sugar, and beat until smooth.
Using a palette knife spread the frosting over the top of the cake. Sprinkle the walnuts over the cake and serve with a nice cup of tea.