Directions

The cake:

1. Preheat the oven to 165 degrees C, gas mark 4.
2. Grease some silicone moulds, or line a rectangular cake mould with parchment paper.
3. In a mixing bowl, sift together all dry ingredients, except the corn flour.
4. Add the oil, carrots and walnuts.
5. Dissolve the corn flour in the soya milk. Pour into the sponge mix and whisk, medium speed, till an evenly mixed consistency.
6. Divide the sponge equally into the moulds or cake pan.
7. Bake 16 "“ 18 min, depending on the size of the mould.
8. Check if a toothpick comes out dry and clean.

The frosting:

1. In a mixing bowl, whisk all ingredients together until light and fluffy consistency.
2. Spoon or pipe on top of the cake.

The carrots: (editor's contribution)

This is perhaps the most "involved" part of the process, and whilst you can use shop-bought cake decorations, many do seem to be made with "Royal Icing" which of course traditionally contains egg or even dairy. Therefore you may well have better luck (and less hassle) making your own if you can't readily find animal-free ones. To make them yourself, the easiest way is using marzipan, and a few drops of orange (or red and yellow) food colouring to get that "carrot" colour. You'll need to get yourself some thin disposable gloves for this and knead a few drops into your marzipan. From there you can mould it  into a ball, roll into  a sausage on a chopping board and shape in your hands until you have a "carrot". Making cake decorations can be quite theraputic and a lot of fun, if you ever modelled plastercine or  play-doh as a child, this may well remind you of those times...

For the stalk, you can either colour some marzipan green the same way, shaping by rolling into thin strands which you then need to cut into 4 short lengths. Bend the strands into v-shapes and push together. Make a hole in the top of your carrot and push your "stalk" in to complete your decoration.  Alternatively, push some short pieces of de-leafed parsley stalks into the ends of your carrots (as long as you're not going to leave them hanging around for ages out of the fridge as you don't want them to wilt!)

Another option if you don't want to "get your hands dirty" (although you probably have already making your cakes   :)   ) then buy pre-made edible starch-based vegan cake decorations online such as these if you wish. I've not personally used these ones, but they do look like they could be worth a try.