Preheat the oven to 180°C. Grease and line 12 mini-Bundt cake tins with baking paper.
Beat the sugar, eggs, buttermilk, and vanilla extract together, gradually mixing in the oil.
Sift together the flour, baking powder, bicarbonate of soda, spices, and salt, then mix into the egg mixture.
Combine the grated carrots and nuts then add to the batter. Pour into the prepared cake tins and bake for approximately 50 minutes.
To make the topping, cream the butter in a food mixer and gradually add half the icing sugar. Beat until fluffy. Add the cream cheese and beat at a slow speed. Add the remaining icing sugar and the vanilla extract. Stop beating as soon as it is incorporated.
Turn the cakes out onto cooling racks and allow to cool completely.
Ice each little cake with a couple of dollops of the icing and a sprinkling of edible flowers.