This cake was created for a baby shower. The cake is a carrot cake covered with a cream cheese icing which is actually quite good for piping, too. You will need a cup of butter, 2 packages of cream cheese (do not use "light" cream cheese), 8 cups of icing sugar, 3 tablespoons of milk, and 1 teaspoon of orange or lemon zest (optional) (in fact, if you are going to use it for piping, omit the zest because it will clog the decorating tips).
You should cream the butter and cream cheese first, and then add the milk and icing sugar, one cup at a time. This icing goes really well with either carrot or banana cake. Have fun with it!