Preheat your oven to 160°C (fan) / 180°C. Grease two mini sandwich tins with melted unsalted butter and dust them with plain flour.

In a large mixing bowl, combine 180g of self-raising flour, 180g of light brown sugar, 1.5 tsp of ground cinnamon, 0.5 tsp of mixed spice, and the zest of one large orange. Whisk until evenly mixed.

In a separate bowl, whisk together 2 large room temperature eggs, 180 ml of sunflower oil, and 1 tsp of vanilla extract until frothy.

Pour the wet mixture into the dry ingredients and whisk gently until just smooth. Fold in 125g of finely grated carrots and 50g of chopped walnuts.

Divide the batter evenly between the prepared mini tins, filling each about 3/4 full. Bake for 20-22 minutes, or until golden brown.

Once baked, remove the tins from the oven and let them cool for about 10 minutes. Then transfer the cakes to a wire rack to cool completely.

In a mixing bowl, beat 100g of softened unsalted butter and 200g of icing sugar together until fluffy. Gradually add 100g of cream cheese until smooth.

Once the cakes are cool, spread a generous layer of frosting between the layers and on top. Add optional orange food coloring and top with walnuts and rosemary.