1. Firstly, start by preheating the oven temperature to 180C/350F.
2. In a large bowl, mix together the dry ingredients: the flours, bicarbonate of soda, cinnamon, and salt, using a spoon.
3. In a separate bowl mix together the ground flaxseeds and the water and let the mixture stand for 2-3 minutes.
4. In another large bowl mix together all the wet ingredients: the oil, milk, grated carrot and Lyle's Golden Syrup. Stir with a spoon to combine. When ready, add the ground flaxseed mixture to the wet mix, stir briefly to combine.
5. Grease a 12-cup mini cake tin (6.5cm each) or 12-cup muffin tin.
6. Combine the wet and dry ingredients and the chopped walnuts.
7. Next, spoon the batter into the prepared cake tin and bake in the oven for about 20min or until risen and golden.
8. Whilst the mini cakes are in the oven combine the frosting ingredients with a spoon in a little bowl. Place in the fridge until the mini cakes are ready to be frosted.
9. When the mini carrot cakes are ready, remove them from the oven and allow them to cool completely.
10. Carefully trim off the rounded top of the mini cakes to create even, flat mini cake layers (we placed them in the freezer for 30 minutes prior, to make this process easier).
11. Next spread about 1 tablespoon of frosting on one of the mini cakes, top with a second, frost again and decorate to your liking with nuts, edible flours or seasonal fruit.