2 cups (300g) self-raising flour
1 1/2 cups (330g) brown sugar
1 cup coarsely grated zucchini
1 cup coarsely grated carrot
1/2 cup (55g) coarsely chopped walnuts
2 tsp ground cinnamon
1/2 tsp ground nutmeg
1 cup (250g) vegetable or canola oil
4 eggs, lightly whisked
250g cream cheese, at room temperature
50g butter softened
1 cup (160g) icing sugar mixture
1 lemon, zested, juiced
1/4 cup (25g) walnuts, extra
Preheat oven to 180c. Grease and line the base and sides of a 10cm x 22cm loaf pan with baking paper, allowing the sides to overhang. Combine flour, brown sugar, zucchini, carrot, walnut, cinnamon and nutmeg in a large bowl. Whisk the oil and egg in a small bowl. Add to the flour mixture. Stir to combine. Pour into prepared pan and smooth the surface.
Bake for 1 hour or until a skewer inserted in the centre comes out clean. Set aside in the pan for 5 minutes before transferring to a wire rack to cool completely.
Use an electric mixer to beat the cream cheese and butter in a bowl until pale and creamy. Add icing sugar and lemon juice. Beat well until combined.
Place the cake on a serving plate. Top with cream cheese icing. Sprinkle with lemon zest and extra walnuts.