Grease two baking trays and preheat the oven to 200C/400F/Gas Mark 6.
Cream the butter, sugar and zest together and beat with a wooden spoon until light and fluffy.
Beat in the egg and rose-water.
Sift in the flour and almonds. Mix well together until you have a thick paste.
Form the paste into 3 sausage-like rolls the dimension of a 2p piece. Slice into 10cm strips and bend these into crescent shapes and place them evenly on the baking trays.
Bake for 12 minutes, until golden. Cool on a rack and dust with the icing sugar.