Put your ready-to-roll icing block in
a large bowl and pour over boiling
water to cover. After 10-15 mins the
icing should be soft. Pour off water, and
mix icing in bowl, adding a dribble more
hot water until you get a smooth, runny
but thickish icing.
Divide evenly in 3 and add a little blue
colouring to one third, and a little blue
and green colouring to another third.
Slice a 20cm square, or a 30 x 20cm
traybake cake into roughly equal,
portion-sized squares, and sit them
on a wire rack above a large tray.
Spoon some icing over each cake to
cover, then decorate with sprinkles,
sugared almonds, mini marshmallows
and small gingerbread men.