Its DD's birthday in a fortnight and I'm still deciding what cake to do for her. She loves Ben & Holly so I thought perhaps I could do the castle. To do the castle, I thought I'd make a traybake, use a cutter to cut circles and then layer it up using buttercream & cut it horizontally rather than vertically. How could I do the grey walls which go around the garden area? Any ideas? For the garden itself, I thought I could either do green fondant icing or dye some dessicated coconut.