1. Beat the butter with the sugar until light and fluffy. Add the eggs one at a time beating between each egg.
2. Combine the flour, vanilla sugar, baking powder and salt in large bowl. In a separate bowl, combine the beetroot, beetroot juice and apple cider vinegar.
3. Carefully fold the flour mixture and the beetroot mixture alternately into the egg mixture. Be careful not to over mix.
4. Pour the batter into a greased springform pan (approx. 24 cm in diameter). Bake in the middle of the oven for approx. 1 hour at 180°C. Remove from the oven and cool completely on a rack.
5. Once the cake is cooled, carefully remove from the pan and slice lengthwise into 2 layers.
6. To make the icing, combine the cream cheese, icing sugar, lime zest and juice. Beat the whipping cream until stiff, then fold into the cream cheese mixture.
7. Put together your cake by placing one cake layer on a serving dish. Spread 1/3 of the icing on top. Place the second layer on top. Spread the rest of the icing all over the cake, creating a smooth surface.
You can substitute beetroot pulp from a juicer for the grated beetroot. The pulp is what is leftover after pressing juice.