After a couple of glasses of wine I agreed to make my friend a carrot cake for a her birthday. The recipe I used was from a friend (she made one for a coffee morning I went to and it looked great) and seemed simple enough; it was three tiers and covered in cream cheese buttercream icing but I wanted to challenge myself.

Making the cake mix went fine, but I don't think I divided it equally enough (tips please!).

The next day I tried to level the cakes with a serated knife but there wasn't much to take off without making the cakes too thin. It also took off a few chunks. Then I made the icing: 600g icing sugar, 100g butter 250g cream cheese. It seemed to curdle after I put in the cream cheese and was pretty wet. I added more icing sugar to make it thicker and put it in a food to processor to get rid of the lumps.

I thought it seemed ready to put on the cake and do a crumb coat but after a few seconds it started dribble off the edge, not helped by the cake being unlevel! I added another layer - same problem. It was reminding me of the leaning tower of Pisa. The top two layers were just sliding off because of the icing.

I couldn't give it to my friend like that so I told her it was a disaster.

Obviously my main problems were the size of the cakes and getting them level, and the consistency of the icing. Any tips would be very welcome.

What recipe did you use?  I tend to bake my carrot cakes in two pans that are 2" high.  This means you can torte them to make 4 1" layers if you want.  For the cream cheese icing, your ingredients need to be room temperature.  The cream cheese will definitely curdle if you try to mix it cold.  I am in the US and I'm almost off to work so I don't have time to convert your measurements, but maybe you needed more icing sugar in the recipe.  I also put my cream cheese icing in the fridge before I work with it, to make it a little stiffer.  Then after the cake is iced I put it in the fridge to make sure the icing holds its shape (if I'm making a less sweet cream cheese icing).

Oh, next time you try, don't drink any wine first.  That may have been your problem.  :P
 

Here is the recipe http://www.redbrick.me/2011/04/hummingbird-bakery-carrot-cake/

I wasn't drunk when I was making it! I just think I wouldn't have agreed to make it had I not been tipsy!:-S

Maybe the cakes should have risen more?

Hmm.  That looks like a pretty basic recipe.  The oil is the same amount that I use in my recipe, only I scale it back to an even cup.  I use 4 eggs in my recipe.  What size pan did you use?
 

The icing recipe looks OK.  I would even have used 125 g butter but there is LOTS of sugar there. Make sure to use full fat brick cream cheese, in my experience the brand is not important with regard to water content but the type is.  The wetness of your icing is a real mystery.

You can divide batter by weight or simply put the same depth into each pan.  

The cake in the recipe picture looks only about 3cm deep, so you would have needed more batter for a 5cm deep cake layer.

When I make carrot cake, I beat the oil eggs and sugar until all the grains of sugar have dissolved.  An extra few minutes but it makes the cake more uniform.  If you double such a  recipe, double the beating time for these ingredients. Maybe next time use a recipe that tells you what size of tin it makes...

Did you use full fat cream cheese? I once tried to make a cake "a bit less unhealthy" by using light cream cheese (Philadelphia) and it was a total disaster, it was pretty much as what you are describing yours was like. I find it virtually impossible to find the brick cream cheese in the UK that BakingIrene suggested, (assuming that's where you are, in Ireland it's difficult but possible in my experience, dont know about else where!) but if you use full fat stuff from a tub it definately helps significantly over the reduced fat versions.

I used 20cm silicone moulds, 2 inches deep.

I never thought about the depth of the batter! D'uh. I was concentrating on how many spoonfuls I was putting in.

Jennifer, I think you have a point. I used extra low fat cream cheese! I had no idea it would have that affect on the icing.