Pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4, and grease and line two 8" cake tins
In a bowl mix together the eggs, light brown sugar, sunflower oil and vanilla extract
Use some kitchen towel to press any excess water out of the grated carrot, then add it to the mixture and fold it in
Add the self raising flour, wholemeal self raising flour, the zest from the orange, cinnamon, ground ginger, and nutmeg. Mix it all in with a whisk until combined
Divide the mixture between the two cake tins and bake for 25 minutes, or until a thin skewer or cocktail stick inserted into the centre of the cakes comes out clean
While the cake is baking, mix the orange juice with the caster sugar until the sugar dissolves. When the cakes are done, poke a few holes in each sponge using a skewer, then spoon the orange juice mixture all over it. Leave the cakes to cool in the tins and let the orange juice fully soak in
To make the buttercream mixed together the butter, cream cheese, icing sugar and marmalade
Spread the buttercream over one of the sponges, top it with the other sponge, then spread the rest of the buttercream over the top of the cake
Decorate with sprinkles as desired